Abstract: A circuit according to an example includes an immitance converter amplifier based on a plurality of transistors of a first conductivity type and a supply transistor coupled between an output of the immitance converter amplifier and a supply for a supply potential, the supply transistor being a transistor of a second conductivity type complementary to the first type.

Abstract: A gas sensor cell using a liquid crystal composite material is provided. The gas sensor cell has recovery capability and can be reused. Upon gas adsorption, the liquid crystal composite material has visually detectable color changes and changes in electrical properties to facilitate the measurement of gas concentration from low to high.

Abstract: A titania nanotube suitable as an optical sensor or gas sensor is provided. The titania nanotube has a length of 1 ?m or more; preferably a diameter of 0.1 ?m or less and an aspect ratio of 100 or more.

Abstract: A gas analyzer apparatus includes a device or platform for supporting a predetermined quantity of a reagent capable of reacting with a predetermined gas to cause a detectable change in a characteristic of the reagent, a reservoir adapted to retain the reagent, a dispenser for dispensing a controlled quantity of the reagent from the reservoir to a predetermined position on the device for supporting the predetermined quantity of the reagent, and a detector that detects the presence of the predetermined gas upon the predetermined gas and the controlled quantity of reagent reacting to cause a detectable change in a characteristic of the reagent detectable by the detector, the detector adapted to detect a change in the controlled quantity of the reagent by detecting the change in the characteristic through the predetermined quantity of the reagent.

Abstract: Detecting air ingredients is obtained, a heater and gas sensitive acting layers are arranged on a substrate, which are connectable to an analyzing unit. Electrical resistances of n acting layers are connected in series; heater is a temperature sensor connected in parallel with this series connection, electrical resistance of heater is smaller than the sum of electrical resistances of acting layers and resistances are connected with a total of n+1 electrical terminals via electrodes so that heater is connected with two terminals and n?1 other terminals are connected with a respective junction that interconnects two acting layers. Heater is intermittently heated so that a predefined constant temperature of acting layers is achieved, temperature of acting layers is acquired by determining electrical resistance of heater; voltages in the series connection of acting layers are analyzed and a concentration of gases are determined from electrical resistances of acting layers.

Abstract: The present invention relates to a method of qualifying ovarian cancer status in a subject comprising: (a) measuring at least one biomarker in a sample from the subject and (b) correlating the measurement with ovarian cancer status. The invention further relates to kits for qualifying ovarian cancer status in a subject.

Abstract: Acoustic wave devices coated with a biolayer are described for the detection target bio-molecules. The acoustic wave device is connected in an oscillator circuit, and the frequency shift ?f resulting from a biomolecular event is recorded. Further described are the use of Rayleigh wave surface acoustic wave devices for vapor phase detection as well as quartz crystal microbalance devices for liquid phase measurements. A biofilm on the surface of the acoustic wave device comprises of a layer of antibodies raised against a specific target molecule or antigen. Signatures for detection events are presented in the form of frequency shifts ?f(t).

Abstract: An apparatus and method for measuring nitric oxide production and oxygen consumption in cultures of adherent cells continuously and without destroying the cells. The method involves flowing growth media through a tube having adherent cells are adhered to the inner surface thereof and then contacting the growth media with an NO or O2 sensor to detect the concentration of NO or O2 in the growth media.

Abstract: Methods for testing oligonucleotide arrays are disclosed including methods for testing the efficiency of nucleotide coupling; methods for testing amounts of deprotected oligonucleotides; methods for determining amounts of depurinated oligonucleotides; and methods of detecting the presence of cleavable structural features, such as double-stranded nucleic acids.

Abstract: There is disclosed a method for detecting the presence of bacterial vaginosis in a female subject comprising the steps of: obtaining a sample from the vaginal region of the subject; detecting acetic acid present in the sample; and correlating the presence of detected acetic acid with the presence of bacterial vaginosis.

Abstract: A BIER vessel evaluates biological indicators for sterilization processes. By flowing gaseous sterilant, such as vaporized hydrogen peroxide, through a chamber (12) before, during, and after introducing the indicators, the indicators are instantaneously exposed to preselected steady state conditions, allowing accurate and reproducible evaluation of the indicator response. A door (32) to an opening (30) in the chamber opens for introducing the indicators to the chamber without appreciably disturbing the steady state conditions therein. After a preselected time, the biological indicators are removed and evaluated for remaining biological activity.

Abstract: A device and method for detecting bacteria in food substances and the like utilizing a three layer composite consisting of a transparent base, an indicator exhibiting color change when exposed to changes in pH, and a gas permeable cover placeable in proximity to the substance. The method utilizes the generation of CO2 gas as a byproduct of bacterial growth which produces carbonic acid lowering the pH of the substance in the region of the composite resulting in an observable color change as in indication of the presence of bacteria.

Abstract: The biosensor involves a specially designed surface which can be optically coupled to a Surface Plasmon Resonance spectrometer. The key components of the biosensor are a bimetallic layer, a self assembled monolayer of chemicals and a layer of biomolecules such as special antibodies. The innovative bimetallic layer combines the sensitivity of silver metal and durability of gold and thus make it an ideal biosensor layer not only for a low volatility gas phase detection but also for a liquid phase detection. The successful application of the biosensor in high explosive substance detection proves that the biosensor is a sensitive and highly specific device for security and anti-terrorism applications, when it is combined with a Surface Plasmon Resonance Spectroscope.

Abstract: A method and apparatus for detection of a small amount of volatile products from a sample using a transducer which changes voltage as a function of contact of the volatile product with the transducer. The apparatus and method are used to detect spoilage of a biological material, such as a food. The apparatus is also used to detect microorganisms and in particular pathogenic microorganisms.

Abstract: This invention relates to a container and method for detecting a specific environmental parameter or combination of parameters, or for determining the effectiveness of a sterilization procedure. The invention relates to test indicators containing controlled volumes of compressed, gas-permeable materials, and modified caps comprising one or more apertures, sterilant permeable inserts, protruding members, or a combination thereof, and to methods for using test indicators for determining the efficacy of different types of sterilization processes. If proper sterilization conditions are not met, the interactive enzyme system remains active, and a color product forms upon the addition of the remaining components of the enzyme system. If the proper sterilization conditions are met, the sterilant destroys the interactive enzymes and no color product is formed. Inactivation of the enzyme system parallels the inactivation of bacterial spores subjected to the sterilization process.

Abstract: A method for detecting an analyte of interest present in a mixture at an ultralow concentration includes selecting a radioactive derivatizing agent comprising a multiphoton-emitting radioisotope moiety and a moiety reactive with the analyte of interest, the radioisotope moeity being bound to the derivatizing agent by a bond that is stable under the conditions employed in the other steps of the method, derivatizing the analyte of interest with the derivatizing agent, separating the analyte of interest from other components of the mixture by chromatography, and detecting the analyte of interest using multiphoton detection. The derivatizing step may be performed before or after fractionation. A radiophore for multiphoton emission enhanced chromatography has a first moeity bound to a multiphoton-emitting radioisotope, and a second moiety that is reactive with a functional group of an analyte of interest.

Abstract: A kit is provided for testing a gas produced from a sample for an absolute amount of a hydrogen sulfide. The kit includes a vessel for receiving the sample to be tested. The vessel includes one or more gas flow passages through which gas within the vessel can leave the vessel. The kit also includes one or more testing tubes. Each testing tube includes a lumen through which gas can flow. The lumen includes a column of medium observable from outside the testing tube and has a length which changes in appearance in proportion to the amount of hydrogen sulfide which has passed through the testing tube. Graduations are included on the one or more testing tubes for indicating the length of the column of medium whose appearance has changed. The kit also includes a coupling mechanism for coupling the one or more testing tubes with the one or more gas flow passages such that gas leaving the vessel passes through the one or more testing tubes.

Abstract: This invention relates to novel apparatus and methods for inserting and positioning a compressible material into a container and for using the container for detecting a specific environmental parameter or combination of parameters, or for determining the effectiveness of a sterilization procedure. Precise positioning of a plug of compressible material in a container has been discovered to provide flexibility necessary for production of indicator systems that vary in their response to sterilizing conditions to reflect the efficacy of sterilizers based on different modes of sterilization and reproduceability necessary for accurate monitoring of each mode. The invention also relates to test indicators containing controlled volumes of compressed, gas-permeable materials and to methods for using test indicators for determining the efficacy of different types of sterilization processes. The test indicator consists of a plurality of interactive enzymes in a container with at least one opening.

Abstract: The invention provides a sensor for detecting an analyte comprising a support for a bioreceptor or biomimic and a detection means, wherein the support can retain a bioreceptor or biomimic and the support and the bioreceptor or biomimic and the detection means can be arranged such that when the sensor is placed in a medium containing a substrate, the substrate contacts the bioreceptor or biomimic and reacts to generate a response which is detectable by the detection means and which is relatable to the concentration of the analyte, and the support comprises a non-volatile organic liquid.

Abstract: The diffusion through a membrane assaying apparatus and method facilitates rapid detection of small or larger molecular weight substances such as hazardous wastes, toxic chemicals or the like by using a semipermeable membrane having a predetermined molecular weight cutoff. The semipermeable membrane is provided as part of a container having a removable barrier which facilitates control of diffusion through the membrane. The assaying method includes the use of a reaction mechanism for detection of a predetermined substance. The reaction mechanism includes one or more reagents which are designed to either react or compete for a substance for which assaying is being performed. By selecting the proper reagents and molecular weight cutoff of the semipermeable membrane, the presence or absence of a reaction such as a color change or production of vapor provides indication whether the substance being assaying for is present in the test sample.

Abstract: A device and method for detecting microorganisms in a specimen by culturing the specimen in a sealable specimen container with a culture medium and detecting microorganisms in the specimen by measuring changes in pressure within the container caused by their metabolic activity during culturing. Pressure changes are measured using a sensor having a deformable section in communication with the container and a piezoelectric apparatus, such that the piezoelectric apparatus is deformed by changes in pressure within the specimen container and an electrical signal is produced by the deformation. The electrical signal is processed to detect any change in the rate of change of pressure, and thus detect the growth of microorganisms.

Abstract: A method for detecting an analyte of interest present in a mixture at an ultralow concentration includes selecting a radioactive derivatizing agent comprising a multiphoton-emitting radioisotope moiety and a moiety reactive with the analyte of interest, the radioisotope moeity being bound to the derivatizing agent by a bond that is stable under the conditions employed in the other steps of the method, derivatizing the analyte of interest with the derivatizing agent, separating the analyte of interest from other components of the mixture by chromatography, and detecting the analyte of interest using multiphoton detection. The derivatizing step may be performed before or after fractionation. A radiophore for multiphoton emission enhanced chromatography has a first moeity bound to a multiphoton-emitting radioisotope, and a second moiety that is reactive with a functional group of an analyte of interest.

Abstract: This invention relates to novel apparatus and methods for inserting and positioning a compressible material into a container and for using the container for detecting a specific environmental parameter or combination of parameters, or for determining the effectiveness of a sterilization procedure. Precise positioning of a plug of compressible material in a container has been discovered to provide flexibility necessary for production of indicator systems that vary in their response to sterilizing conditions to reflect the efficacy of sterilizers based on different modes of sterilization and reproduceability necessary for accurate monitoring of each mode. The invention also relates to test indicators containing controlled volumes of compressed, gas-permeable materials and to methods for using test indicators for determining the efficacy of different types of sterilization processes. The test indicator consists of a plurality of interactive enzymes in a container with at least one opening.

Abstract: A method for identifying a microorganism is described that includes abstracting gas or vapor associated with the microorganism from a detection region and flowing the same over an array of sensors of which an electrical property varies according to exposure to gases or vapors and observing the response of the sensors. An apparatus for detecting a microorganism is also disclosed having a detector means for detecting a gas or vapor associated with the microorganism which includes an array of sensors of which an electrical property varies according to exposure to the gases or vapors.

Abstract: This invention relates to methods and the use of biological indicator systems to assess and determine the effectiveness of sterilization processes comprising the steps of contacting an indicator comprising microbial spores with a sterilant; a medium selected to germinate the spores; and calculating a germination rate of the exposed spores to determine the effectiveness of the sterilization process. A method for rapidly determining the effectiveness of the gemination rate of microbial spores with spore viability is also described.

Abstract: There are described a simple examination method of infection with Helicobacter pylori possibly presenting in a gastric mucosa, and a device therefor. The examination is conducted by collecting gas in gastric cavity, and measuring mainly ammonia and additionally organic amines which are generated due to activities of the bacilli. The measurement is carried out by leading the gas in gastric cavity into oral cavity by vomiting-reflex, and sucking the gas by a metering suction pump through a gas detection tube to read-out a length of color-changed area in the gas detection tube.

Abstract: A method for rapidly determining mold growth on feed is disclosed. The method comprises placing a sample of feed containing mold spores in a closed container; maintaining an environment that will support rapid mold growth; measuring the change in concentration of oxygen and/or carbon dioxide; and correlating the concentration change with the rate of mold growth.

Abstract: A device and method for detecting microorganisms in a specimen by culturing the specimen in a sealable specimen container with a culture medium and detecting microorganisms in the specimen-by measuring changes in pressure within the container caused by their metabolic activity during culturing. Pressure changes are measured using a sensor having a deformable section in communication with the container and a piezoelectric apparatus, such that the piezoelectric apparatus is deformed by changes in pressure within the specimen container and an electrical signal is produced by the deformation. The electrical signal is processed to detect any change in the rate of change of pressure, and thus detect the growth of microorganisms.

Abstract: A method for measuring the presence of traces of substance in air by providing in a cuvette a substrate reacting with the substance by changing its opacity, passing at a defined flow rate air from the air body to be checked through the substrate, measuring the development of opacity. A portable apparatus comprises a housing (1, 101) holding a cuvette (131) containing a substrate (3, 103), an inlet tube (28) leading to the bottom of the cuvette, a pump (13) sucking air from the cuvette through a flow monitor (138) controlling the pump, a spectrophotometer lamp (19, 119) and a photo-diode (20) on opposite sides of the cuvette (131), a monitor monitoring the level (4, 104) of the substrate in the cuvette, and a monitor (23, 123) monitoring the temperature of the substrate, a computer (24) receiving signals from the photodiode (20), the level monitor, and the temperature monitor to calculate a temperature and level compensated indication of the substrate opacity.

Abstract: The invention is directed to a detecting device for detecting gaseous substances and aerosols with the aid of an enzymatic reaction. This reaction takes place between a reactant and an enzyme which, on the one hand, is exposed to the substance to be detected and, on the other hand, is held by a carrier which in the form of a porous holder is in contact with a solution activating and maintaining the enzymatic reaction. The properties of the solution are changed by the enzymatic reaction and are evaluated. The detection device is so improved that a capability for evaluation is made possible which is quantitative and which is specific for a particular substance to be detected. The substance to be detected as a reactant can be stoichiometrically transferrable into a reaction product for quantitatively determining the substance to be detected by means of an enzymatic reaction.

Abstract: A pickled vegetables fermentation detector is the sensor for sensing kimchi curing which converts variables depending on the state of kimchi curing into an electric signal and is provided with an air bubble generator, gas collector and detector, in which the inside of the air bubble generator is divided into an upper compartment and lower compartment; gas generated in curing pickled vegetables is collected in the upper compartment to a predetermined quantity and gas is transported to the lower compartment at a predetermined pressure, and the main body of the lower compartment connected to one side of the upper compartment is composed of an air bubble homogeneity device expanded to the lower portion and inserted to a predetermined fluid in the inside of the lower compartment; one wall of a pair of oppositely disposed side walls is thicker than the other, and thickness of the walls is cut off at a predetermined height in the lower wall of both walls and a transparent panel is installed in the proximity of those

Abstract: A direct-read exposimeter for providing a visual, graded measurement of color variation corresponding to different ranges of dosage exposure to a polluting gas in the atmosphere over a given time period. The exposimeter includes a color-forming member and at least one gas-diffusion control member within an enclosure formed between a base and a cover. The cover has a number of openings exposed to the atmosphere in alignment with a number of separate diffusion zones formed in the gas-diffusion control member.

Abstract: Selective detection of microorganisms is achieved by a screening technique in which radioactively labeled, low-molecular-weight metabolites produced by microorganisms to be detected reach an adsorption medium through a semipermeable medium which passes the labeled metabolites but blocks the labeled incubation medium. The adsorption medium is then subject to analysis, such as autoradiography, to detect the presence of the labeled metabolites.

Abstract: Selective detection of microorganisms is achieved by a screening technique in which radioactively labeled, low-molecular-weight metabolites produced by microorganisms to be detected reach an adsorption medium through a semipermeable medium which passes the labeled metabolites but blocks the labeled incubation medium. The adsorption medium is then subject to analysis, such as antoradiography, to detect the presence of the labeled metabolites.

Abstract: A simple device functioning as a radiorespirometer is a petri dish with a modified cover for quantitating an amount of CO.sub.2 evolved by living cultured cells. The device is a plastic culture dish having a culture surface circumscribed by a continuous sidewall. A removable flat plastic cover has a flat inside face and an annular collar around the face that fits against a sidewall. The collar is maintained in substantially gas-tight relationship against the sidewall by an elastic band or tightly mating surfaces. An opening through the cover is sealed by a gas-impervious material, such as a plastic film, that can be penetrated by a needle to introduce acid into the dish for terminating culture growth and lysing the cells. A collector tube is removably secured to the inside face of the cover and contains a CO.sub.2 trapping material, such as hyamine (methylbenzethonium hydroxide). The culture medium is provided with a cell substrate that contains radioactive carbon, and radioactive CO.sub.

Abstract: A device for determining the aerobic biodegradability in a composting installation of at least one product includes at least two reactors, a temperature device for maintaining the reactors at a temperature above the ambient temperature, a device for passing gas which contains oxygen through the reactors, a device for separately collecting outflowing gas from each of the reactors, a measuring/calculating device for determining the amount of CO.sub.2 in the outflowing gas of each reactor and a calculating device for determining the aerobic biodegradability of the at least one product based on the measured/calculated amount of CO.sub.2 in the outflowing gas of each reactor.

Abstract: A pressure/vacuum method and instrument for detecting biological activities in blood culture vials, that is non-invasive, does not require chemical sensors, does not require high-brightness short-wavelength light sources, is safe against eventual extreme high pressure values, and is head-space-temperature compensated. A culture medium and blood specimen are introduced into a sealable glass vial. The normally incompressible fluid suspension is made compressible through the use of a partially inflated gas bag submerged within the medium. The changes in fluid position that result from bacterial growth related pressure changes within the vial head space are measured to detect biological activities.

Abstract: A venting apparatus for a bubble contactor used to dissolve oxygen in water prior to introducing the water into a biological fluid bed reactor that, under aerobic conditions, removes potentially combustible contaminants from the water for removing fuel constituents from water. The venting apparatus includes a float-operated valve wherein the float senses the existence of a gas space in the upper part of the bubble contactor and is operable to open the valve to vent the gas space. Such a space is potentially capable of supporting a combustible mixture of oxygen and fuel constituents which could be ignited by a source, such as a static electric discharge. The valve remains closed under normal conditions when no significant gas space exists to prevent the needless waste of oxygen.

Abstract: A venting apparatus for bubble contactor employed in liquid treatment apparatus for removing fuel constituents from water. The liquid treatment apparatus includes an oxygenator for dissolving oxygen in the water prior to its introduction into a biological fluid bed reactor to support biological action in the reactor. The oxygenator includes a bubble contactor having a bubble contact chamber, and a venting apparatus for venting the bubble contactor when the bubble swarm in the contact chamber grows too large. The venting apparatus includes a lower valve assembly including a valve having a float mechanism for sensing unacceptable accumulations of gas bubbles in the lower part of the bubble contactor, below the desired lower level of the contact zone. The float also functions to open the valve to release the excess undissolved gas.

Abstract: The present invention relates to immunoassay methods for detecting and measuring the amount of an analyte in a sample by means of generic anti-hapten antibodies. Also disclosed are multi-analyte immunoassay methods. Reagents, devices, and kits using the anti-hapten antibodies are also disclosed. The present invention also relates to dyed erythrocytes, preferably fixed, which are coated with antibodies. Also disclosed is the use of these dyed erythrocytes in agglutination assays to detect and measure the presence of an analyte in a sample. The analyte can be a hapten, an antigen, or an antibody. Also included are agglutination assays, compositions and kits using these dyed and coated erythrocytes.

Abstract: Method for determining in an accelerated manner the biodegradability of at least one product under anaerobic conditions which are similar to those in a dump, characterized in that a mixture with a dry substance content of between 25 and 50% is prepared with more than 80 weight-% of an active anaerobic inoculum and less than 20 weight-% of the product, on the one hand, at least one quantity of this mixture and, on the other hand, at least one quantity of the inoculum is subjected in the same manner to a fermentation at a temperature of between 30 and 60 degrees Centigrade in anaerobic conditions, the amount of biogas that is released with both these fermentations is separately measured or calculated, starting with these amounts the amount of biogas produced by the product alone is deduced and starting with the latter amount the degradability of the product itself is determined, this is the amount of carbon which was degraded from the product and converted into CO.sub.2 and CH.sub.4.

Abstract: An apparatus for detecting gaseous aldehydes is disclosed which contains a detachable aldehyde capturing system and an aldehyde detection system. The gaseous aldehyde is passed across a semipermeable membrane with a solvent on the other side of this semipermeable membrane to dissolve and absorb the aldehydes from the gas. This system permits the concentration and detection of low concentrations of gaseous aldehyde in the sample for efficient measurement. The aldehyde dehydrogenase to produce NADH in an amount corresponding to the amount of aldehyde in the solvent. The aldehyde detection system measures the amount of NADH produced.

Abstract: A method and apparatus for detecting a toxin whereby a yeast culture is monitored for the release rate of one or more metabolic products before and after the inclusion of a test sample and a decrease in the release rate of the metabolic products indicates the presence of a toxin on the test sample. The method contemplates the use of carbon dioxide-free air as a scrubbing gas to remove carbon dioxide from the media for testing.

Abstract: The present invention relates to a device and method of detecting microorganisms in a rapid manner and increasing the number of microorganisms detected during the culturing of a sample by the addition of resinous and non-resin adsorbents and molecular sieves in the growth media. These agents have been found to neutralize or remove inhibitory and antimicrobial substances found in samples and media.

Abstract: A method and apparatus for detecting the presence of biological activity in a sample of material. In the method, a sample of the material is placed in a closed container with a growth medium which includes a carbon source which may be metabolized to produce carbon dioxide. The medium with the sample therein is exposed to conditions conducive to the occurrence of normal metabolic process for a period of time sufficient to cause production of CO.sub.2 by the metabolism of the carbon source. Thereafter, the presence of CO.sub.2 in the gaseous atmosphere above the medium is detected by measuring the infrared absorbance of the gaseous atmosphere with the container by passing an infrared beam through the container and the gaseous atmosphere and detecting the infrared absorbance of the gaseous atmosphere.

Abstract: A detector for enzymatically determining components in gases and aerosols and includes a porous filter disposed in a housing. The filler absorbs the aqueous reagent solution, the substrates and the enzymes and is brought into communication with a sample to be investigated. The detector of the invention is improved in that a separate preparation of the components needed for the detection takes place in the housing itself. The components combine without additional ancillary equipment or manual movements. The components are combined in that a porous filler is accommodated in a holder and is tightly held thereagainst and a filler tip projects outwardly therefrom. The filler tip is dipped in a supply vessel containing the reagent solution. A penetratable cover membrane which is impermeable to water is arranged between the filler tip and the supply vessel.

Abstract: A unique hollow fiber bioreactor system and method for the propagation of cells and the production of various cell propagation products is described. The system and method include the use of a flow block holder which allows a dissolved oxygen probe to be calibrated at the same pressure as the media in the bioreactor system.

Abstract: A personal dosimeter for measuring the average concentration of undesirable contaminants gases such as nitrogen oxide includes a gas permeable web-like wafer formed of a material inert to polyamine. The wafer has a surface area having a numerical value at least one thousand times the value of the axial width of the wafer. The wafer is soaked in an absorptive medium not containing the ambient contaminant gas to be measured. The wafer, so soaked, is inserted within a gaseous impermeable housing from which the wafer may be selectively release and re-inserted. During an interval of release of the wafer, it is exposed for a predetermined interval of time to the ambient atmosphere. After re-insertion, the dosimeter is taken to an analysis site at which the wafer is removed and the molar concentration of products reaction with the atmospheric contaminant is measured.

Abstract: A method for identifying a microorganism is described that includes abstracting gas or vapor associated with the microorganism from a detection region and flowing the same over an array of sensors of which an electrical property varies according to exposure to gases or vapors and observing the response of the sensors. An apparatus for detecting a microorganism is also disclosed having a detector means for detecting a gas or vapor associated with the microorganism which includes an array of sensors of which an electrical property varies according to exposure to the gases or vapors.

Abstract: A method and device for detecting bacteria by forming an immunoassay ladder sing a biological substance (Ag) adsorbed onto a surface, to which has been added an immunological biochemical ladder (Ab) and beta-galactosidase enzyme (gal) to form a Ag-Ab-gal system. The system is added to an aqueous solution of an enzyme selected from ortho-nitrophenylgalactopyranoside and ortho-nitrophenylgalactosidase enzyme. The enzyme reacts with the gal to produce ortho-nitrophenol (ONP) such that the amount of ortho-nitrophenol (ONP) produced may be detected by measuring the vapor pressure generated by the ONP using an ion mobility spectrometer monitor. The pressure of the ONP is in proportion to the amount of biological substance present in the system. In a preferred embodiment, the ion mobility spectrometer monitor includes display means for indicating the quantity of bacteria measured.