Abstract: FRET measurement uses a FRET probe that includes a probe element X containing a donor fluorescent substance and a probe element Y containing an acceptor fluorescent substance and enables FRET to occur when the probe element X and the probe element Y approach to each other or bind together. The modulation frequency of laser light with which the FRET probe is irradiated is adjusted to an optimum modulation frequency that maximizes a difference between the phase difference of donor fluorescence emitted from the donor fluorescent substance with respect to intensity modulation of the laser light at the time when FRET occurs and the phase difference of donor fluorescence emitted from the donor fluorescent substance with respect to intensity modulation of the laser light at the time when FRET does not occur.

Abstract: The present invention provides an apparatus for analyzing particles in a solution including a unit configured to place a flow cell having a flow path for flowing a sample solution containing the particles; a unit configured to illuminate the sample solution flowing through the flow path of the flow cell; a photodetector that detects a scattered light and/or fluorescence generated from the particles in the sample solution; and a unit configured to analyze the particles based on their signal intensities detected by the photodetector, wherein the flow cell has the flow path formed in a substrate, a reflection plane is formed on the side surface of the flow path, the reflection plane leads the lights generated in the flow path of the flow cell and advancing in the substrate in-plane direction to a specified region of the surface of the flow cell, and the photodetector detects the light exiting from the specified region to the outside.

Abstract: The present invention provides multi-parameter analysis methods for determining the presence or absence of pre-cancerous or cancerous cells in a cervical sample and for screening cervical abnormality in a cervical sample. The invention also provides an apparatus and automated methods for screening cervical abnormality in a sample. The invention further provides a sampling device and a sample collection assembly for collecting cell samples, including cervical samples.

Abstract: A fluorimetric system, apparatus and method are disclosed to measure an analyte concentration in a sample. A sensor reagent housing is also disclosed which comprises a channel and a porous medium having an analysis chemistry reagent, such as a nucleic acid analysis chemistry reagent. The apparatus and system are portable for field use, with an apparatus housing having a size adapted to fit into a user's hand. An apparatus also includes a sensing chamber and cover, a user interface, a light source, a photomultiplier tube, an amplifier, an A/D converter, a memory, and a processor. In various embodiments, the processor performs a data fitting, determines a sample reaction rate parameter, and determines the analyte concentration from a comparison of the sample reaction rate parameter with stored calibration data. The processor may also generate the calibration data and site-specific offset factors, and modify the calibration data using an offset factor.

Abstract: The present invention provides a biosensor system comprising a light source, a cartridge adapted to be illuminated by said light source, a light detector adapted for detecting a signal originating from the cartridge, an illumination control means adapted to vary the illumination of the cartridge between at least two different states, a means for generating a first oscillation with a first frequency, and a means for generating a second oscillation with a second frequency, wherein the frame rate of the light detector is triggered by the first oscillation and the illumination control means is triggered by the second oscillation.

Abstract: The invention is directed towards methods and compositions for identifying the amount of hydrofluoric acid in a buffered oxide etching composition. In buffered oxide etching compositions it is very difficult to measure the amount of hydrofluoric acid because it has varying equilibriums and it is toxic so it hard to handle and sample. When used to manufacture microchips however, incorrect amounts of hydrofluoric acid will ruin those chips. The invention utilizes a unique method of spectrographically measuring the hydrofluoric acid when in contact with added chromogenic agents to obtain exact measurements that are accurate, immediate, and safe.

Abstract: Disclosed is a sample holding carrier allowing samples to be measured accurately, and a fluorescence detection device for use with the sample holding carrier. A biosensor substrate includes a base substrate, a plurality of wells formed on a first surface side of the base substrate; and grooves formed on the first surface side of the base substrate separately from the wells and generating fluorescence under exposure to excitation light. The fluorescence detection device applies excitation light to the grooves, thereby figuring out the level of the fluorescence to be detected from the biosensor substrate. As a result, the fluorescence detection device can amplify the detection signals of the fluorescence generated when the excitation light is applied to the wells to an appropriate level, thereby accurately detecting the fluorescence generated in the samples.

Abstract: A convenient technique allows detecting fluorescence emitted in the channel with a uniformly high detection sensitivity and a good reproducibility. On the front face side of a plate-like body 11, a groove-shaped introduction channel 12 and separation channel 14 are formed. In this micro-channel chip 10, on the inner faces of a groove constituting the separation channel 14 formed in a surface of the plate-like body 11, there is formed a fine particle layer 20 provided by sintering fine particles having an average particle diameter of 10 to 500 nm mainly composed of zinc oxide (ZnO) or titanium oxide (TiO2).

Abstract: Systems and methods for detecting the presence of biomolecules in a sample using biosensors that incorporate resonators which have functionalized surfaces for reacting with target biomolecules. In one embodiment, a device includes a piezoelectric resonator having a functionalized surface configured to react with target molecules, thereby changing the mass and/or charge of the resonator which consequently changes the frequency response of the resonator. The resonator's frequency response after exposure to a sample is compared to a reference, such as the frequency response before exposure to the sample, a stored baseline frequency response or a control resonator's frequency response.

Abstract: A cell for conducting electrochemiluminescence measurements is disclosed. The cell in one embodiment provides a measurement cell housing having a cavity, a fluid inlet channel for inducing fluid into the cavity and a fluid outlet channel for discharging fluid from the cavity at axial ends. The cell also provides at least one working electrode and a counter electrode on or in the cavity, and an optical viewing element for observing electrochemiluminescence effects in the cavity, wherein the fluid inlet channel has an at least approximately continuous curved course in a transition area to the cavity so that the fluid inlet channel at its end which is joined to the cavity is shaped in such a manner as to constitute a continuous course of the transition between the fluid inlet channel and the cavity to generate a largely steady flow profile when inducing fluid into the measurement cell cavity.

Abstract: Analyte sensors having antioxidant protection are disclosed. By combining antioxidant and/or scavenger agents into polymer matrices that contain sensor moieties, the sensor moieties are protected from reactive oxygen species. Also disclosed are methods of making analyte sensors and methods of inhibiting oxidative degradation of sensing components in hydrated, polymerized analyte sensor systems.

Abstract: An optic light guide test sensor comprises a light guide, a reagent-coated membrane, and a mesh layer. The reagent-coated membrane and the mesh layer are attached to the light guide at an output end of the light guide. The light guide test sensor is adapted to be used to test the level of an analyte in a biological fluid sample when used with a readhead. A method of manufacturing the light guide test sensor involves providing a plurality of light guides, providing a strip of reagent-coated membrane, and providing a strip of mesh layer. The reagent-coated membrane and mesh layer are attached to the light guides by ultrasonic welding. The reagent-coated membrane and mesh layer may also be attached to the light guides by adhesive.

Abstract: The invention is directed towards methods and compositions for identifying the amount of ammonium acid in a buffered oxide etching composition. In buffered oxide etching compositions it is very difficult to measure the amount of ammonium acid because it has varying equilibriums and it is toxic so it hard to handle and sample. When used to manufacture microchips however, incorrect amounts of ammonium acid will ruin those chips. The invention utilizes a unique method of spectrographically measuring the ammonium acid when in contact with added chromogenic agents to obtain exact measurements that are accurate, immediate, and safe.

Abstract: [Problem] To provide a sensor chip for SPFS measurement, by which, irrespective of environmental conditions, fluctuations are low in characteristics such as signal, noise, or detection sensitivity, quantitative property can be ensured, and a highly precise and accurate SPFS measurement can be carried out. [Solution] A sensor chip for SPFS measurement which has a dielectric member having been produced by carrying out injection molding of a resin, when viewing from the metal thin film-formed surface side of the dielectric member and taking as b the distance of the side end surface position of the resin inlet to the position on the metal thin film-formed surface that is farthest from the side end surface position of the resin inlet, the center of a ligand immobilization part is located in the area between the 3b/8 position and the 6b/8 position from the side end surface position of the resin inlet.

Abstract: A method of determining a normalized quantity of an analyte adhering to beads in a detection area of a bead-based assaying system, the method comprising: a) causing a complex of the analyte to fluorescently or chemically emit a first light, or to release a dye; b) measuring an integrated intensity of the first light emitted from the beads in the detection area, or a concentration of the dye released from the beads in the detection area, or both; c) causing light to interact with the beads in the detection area, the interaction not depending on whether or how much analyte is adhering to the beads; d) measuring a second light resulting from the interaction with the beads which does not depend on the analyte; and e) determining the normalized quantity of analyte from the integrated intensity of the first light or concentration of the dye or both, and from the measured second light.

Abstract: The present application is directed to a technological platform with integrated microfluidic and optical modules for bio-detection. The platform enables in-situ detection by integrating fluidics with optical source and detection capabilities within a fabricated microchip. The platform is a polymer-based microfluidic chip having integrated excitation source and detection elements in a vicinity of a microfluidic reaction chamber configured to contain a micro-volume of a test sample. The principle of detection is based on an excitation source induced fluorescence of the test sample within the microfluidic reaction chamber.

Abstract: A microchip capable of sending liquid in a micro flow channel to a predetermined place irrespective of the pressure difference and sending a mixture of two or more liquid masses to a predetermined place even if the channel structure is simple. The microchip comprises an intermediate reservoir portion provided in a micro flow channel and adapted for temporarily holding liquid sent through the micro flow channel. The microchip is characterized in that the intermediate reservoir portion has a side channel, the volume of the intermediate reservoir portion is smaller than the total volume of the liquid sent into the intermediate reservoir portion, the side channel is provided for communication of a micro flow channel on the upstream side of the intermediate reservoir portion with a micro flow channel on the downstream side thereof, and the cross-section area of the side channel is smaller than that of the micro flow channel.

Abstract: An instrument for monitoring replication of DNA is provided.

Abstract: A sample support structure comprising a sample support manufactured from a semiconductor material and having one or more openings therein. Methods of making and using the sample support structure.

Abstract: The invention describes novel chemiluminescence electrode devices and their novel properties to enable achieving luminescence signal by electrical excitation by cathodic or bipolar pulses in aqueous electrolyte solutions. These devices form a significant improvement in construction of cheap and reliable means for especially diagnosis of health conditions in point-of-need purposes.

Abstract: A microchip is provided. The microchip includes an incident surface configured to receive light transmitted from a light source, the light being received from an incident direction and a back surface that is opposite the incident surface, the back surface including a portion that is configured to reflect light transmitted from the light source away from the incident direction.

Abstract: An optical measuring apparatus and method for analysis of samples contained in liquid drops provided by a liquid handling system has a liquid handling tip. A light source irradiates the liquid drop; a detector measures sample light; and an optics system with first optical elements transmits irradiation light, and a processor processes the measurement signals. The liquid drop is suspended at the liquid handling orifice of the liquid handling tip in a position where the liquid drop is penetrated by a first optical axis defined by the light source and the first optical elements. The liquid drop is physically touched only by the liquid handling tip and the liquid sample inside the liquid handling tip. A mutual adaption of the size and position of the liquid drop with respect to the first optical elements is achieved.

Abstract: A method of measuring the fluorescence of a fluorescent marker compound dissolved or dispersed in a bulk material includes: (a) measuring a characteristic of the fluorescence of a mixture of said bulk material and said fluorescent marker compound; (b) quenching the fluorescence of the fluorescent marker compound to produce a quenched mixture; (c) measuring the characteristic of the fluorescence of the quenched mixture; (d) comparing the fluorescent characteristic of the mixture with the fluorescent characteristic of the quenched mixture; and (e) correcting the measured fluorescent emission characteristic for the effects of the absorbance of the bulk material. The measurement may be further corrected to account for the absorbance of the material which is also known to have an effect on the measured fluorescence. A method of tagging and identifying a bulk material with a fluorescent marker compound, and an apparatus for carrying out the methods are also described.

Abstract: A method and a device for the assessment of at least one parameter of particles in a liquid analyte material are disclosed. The method comprises providing a device having a sample compartment with an exposing domain, an inlet through which a volume of a liquid sample representing the analyte material can been introduced, and a flow system comprising at least a channel allowing at least a portion of the volume of the liquid sample to flow within the device. The volume of the liquid sample passes into the exposing domain of the sample compartment, which can quantitatively detect spatial image data and process the detected image electromagnetic signals from the sample in the exposing domain of the device. A spatial image representation of the exposing domain, and processing the detected image presentation obtaining the assessment of the at least one parameter is generated in the device.

Abstract: The subject invention presides novel devices and methods for the measurement of nitric oxide in biological samples, including wound fluid samples. These advantageous devices and methods can be used for clinicians to monitor the wound's nitric oxide metabolism and/or response to treatment.

Abstract: Disclosed are an apparatus and method for separation analysis of mannose-6-phosphate (M6P) by post-column fluorescence detection method. The apparatus is based on chromatography, and includes a column with a solid phase having affinity for phosphate, a flow path for the eluate, a heater installed on the flow path for M6P and a basic amino acid to react by heating the eluate in the flow path, and a fluorescence detector installed downstream of the heater for continuously irradiating the eluate with excitation light and measuring the intensity of the emission, and may include in the flow path a supply channel for addition of a basic amino acid between the column and the heater. The method is characterized in that it uses the apparatus and a second mobile phase consisting of a second buffer containing phosphate of predetermined concentration and adjusted to a predetermined pH.

Abstract: A chilled reagent container comprises a reagent vessel containing part for containing therein a plurality of reagent vessels, a container lid including a container lid hole through which the reagent vessels contained by the reagent vessel containing part are accessible, and a cooling block for cooling the reagent vessels contained by the reagent vessel containing part, wherein the container lid slides to be changeable between an opened situation wherein the reagent is accessible from an outside and a closed situation wherein the reagent is prevented from being accessed from the outside, wherein the chilled reagent container further comprises a reagent container packing including another hole through which the reagent vessels are accessible and arranged between the container lid and the reagent vessel containing part to be pressed against the container lid.

Abstract: The present invention provides a biosensing device, comprising an input unit, an analysis unit, a process unit, and a set unit for storing resulting data values as the basis for calibrating the biosensing device, to set up the calibration parameters of a strip of the biosensing device.

Abstract: A chemo-mechano-chemical (C1-M-C2) system includes a base supporting an actuatable structure, said structure comprising a functionalized portion and being embedded in an environmentally responsive gel capable of volume change in response to an environmental stimulus; a first fluid layer disposed over the base and in contact with the actuatable structure, said first fluid layer comprising the environmentally responsive gel; and a second fluid layer in contact with the actuatable structure, wherein the layers are positioned such that the functionalized portion is in contact with the second layer in a first relaxed state and in contact with the first layer in a second actuated state and wherein the functionalized portion interacts with at least one of the layers to provide a chemical or physical response.

Abstract: A fluorescent sensor includes a detecting substrate, an indicator, a filter layer, a light blocking layer, and an LED chip. In the detecting substrate, a PD element for converting fluorescence into electric signals is positioned on wall surfaces of a through-hole which penetrates a first main surface and a second main surface. The indicator is arranged inside the through-hole and generates fluorescence of intensity corresponding to analyte density when the indicator receives excitation light. The filter layer covers the PD element, transmits fluorescence and blocks excitation light. The light blocking layer, through which an analyte can pass, covers an opening of the first main surface of the through-hole. The LED chip covers a region just below an opening of the second main surface of the through-hole, and generates excitation light.

Abstract: An instrument for fluorometric assays in liquid samples is disclosed. The instrument may include multiple optical channels for monitoring a first fluorophore associated with a target analyte and a second fluorophore associated with a control. The disclosed instrument finds utility in any number of applications, including microfluidic molecular biological assays based on PCR amplification of target nucleic acids and fluorometric assays in general.

Abstract: An object of the present invention relates to providing a nucleic acid analyzer capable of testing a plurality of test items in parallel, and of obtaining high efficiency of specimen processing even if the test item or a measuring object is changed. The present invention relates to an analyzer including a carousel rotatable about a rotation axis, a plurality of reaction containers held along a circumferential edge of the carousel, and at least one detector having a light source for irradiating the reaction container with excitation light and a detection element for detecting fluorescence from a reaction liquid in the reaction container. The detector is removable. By attaching a desired detector, it is possible to perform fluorescence measurement in response to the test item. According to the present invention, it is possible to test a plurality of test items in parallel, and even if the test item or the measuring object is changed, the high efficiency of specimen processing can be obtained.

Abstract: A microfluidic device for mitochondria analysis includes an inlet coupled to a first access channel, an outlet coupled to a second access channel, and a plurality of trapping channels fluidically coupled at one end to the first access channel and fluidically coupled at an opposing end to the second access channel, each trapping channel has a cross-sectional dimension about 2 ?m in one direction and a cross-sectional dimension between about 0.45 and about 0.75 ?m in a second direction.

Abstract: Techniques, apparatus, material and systems are described for implementing a three-dimensional composite mushroom-like metallodielectric nanostructure. In one aspect, a surface plasmon based sensing device includes a substrate and a layer of an anti-reflective coating over the substrate. The surface Plasmon based sensing device includes a dielectric material on the anti-reflective coating shaped to form a 2-dimensional array of nanoholes spaced from one another. Also, the surface Plasmon based sensing device includes a layer of a metallic film formed on the 2-dimensional array of nanoholes to include openings over the nanoholes, respectively, wherein the sensing device is structured to support both propagating surface plasmon polariton (SPP) waves and localized surface plasmon resonant (LSPR) modes.

Abstract: A method for the enumeration of micronucleated erythrocyte populations while distinguishing platelet and platelet-associated aggregates involves the use of a first fluorescent labeled antibody having binding specificity for a surface marker for reticulocytes, a second fluorescent labeled antibody having binding specificity for a surface marker for platelets, and a nucleic acid staining dye that stains DNA (micronuclei) in erythrocyte populations. Because the fluorescent emission spectra of the first and second fluorescent labeled antibodies do not substantially overlap with one another or with the emission spectra of the nucleic acid staining dye, upon excitation of the labels and dye it is possible to detect the fluorescent emission and light scatter produced by the erythrocyte populations and platelets, and count the number of cells from one or more erythrocyte populations in said sample.

Abstract: Provided is a microbead analysis method for a microbead. The microbead is formed in a columnar shape having a top surface and a bottom surface facing each other, as placed almost in parallel, and a side surface extending therefrom, and carries an identification pattern formed on at least one of the top surface and the bottom surface and a substance immobilized on a surface thereof having affinity to an analyte substance. The method includes detecting fluorescence emitted from the microbead surface due to interaction of the analyte substance with the substance having affinity to the analyte substance from a region including a region of the top surface and the bottom surface where there is no identification pattern formed and the side surface.

Abstract: A water-quality monitoring system for an aquatic environment that includes a monitoring unit and a chemical indicator wheel designed and configured to be submerged in the water being monitored. The chemical indicator wheel includes a holder that supports a number of chemical indicators selected for use in measuring levels of constituents of the water. When in use, the wheel is drivingly engaged with a monitoring/measuring unit that includes at least one reader for reading the chemical indicators. In some embodiments, each apparatus includes a plurality of immobilized-dye-based chemical indicators that undergo an optically detectable physical change as levels of one or more constituents of the water change. Also disclosed are a variety of features that can be used to provide the monitoring system with additional functionalities.

Abstract: A sensor that detects a fuel property of a mixed fuel of a biofuel and a hydrocarbon fuel includes: a light emitting device that emits light with a wavelength of 250 nm to 400 nm onto the mixed fuel; and a light receiving device that receives light emitted by the mixed fuel under the effect of light from the light emitting device and generates an output corresponding to the received light. When the fuel property is determined, in a case where the mixed fuel is irradiated by light with a predetermined wavelength generated due to voltage application to the light emitting device, the light emitted by the mixed fuel is detected by the light receiving device. The fuel property of the mixed fuel is detected according to the detected light.

Abstract: A chloride ion fluorescence detection method and device, and a use thereof. The chloride ion fluorescence detection method utilizes chloride ions to influence luminescence characteristics of some photoluminescent substances to change the emission spectrum of the photoluminescent substances. The concentration of the chloride ions is detected through two processes comprising the fiber surface film forming and test liquid preparation of a fluorescent reagent sensitive to the chloride ions and measurement of information of fluorescence peak wavelengths or intensities. The method can be applied to the online assessment of the corrosion environment of steel bar concrete or the measurement of chloride ions in a laboratory.

Abstract: A method of rapidly detecting trace materials including biohazards, toxins, radioactive materials, and narcotics in situ is disclosed. A corresponding apparatus is disclosed. A trace of the material is collected on a pad of the card component, collected by swiping the pad on suspected surface or exposure to the suspected air volume. A novel card component is disclosed that when inserted in a chemical detection unit (CDU), releases reaction chemicals from flexible walled capsules in desired sequence. The exposed pad containing trace material and chemicals are heated in the chemical detection unit to produce a spectral pattern that is analyzed by the optical electronics in the CDU and results are displayed, stored and/or transmitted over a communications network.

Abstract: The present invention comprises methods and systems that use acoustic radiation pressure.

Abstract: The present invention relates to an immunoaffinity device for capturing one or more analytes present at high or low concentrations in simple or complex matrices. The device is designed as a modular, multi-task immunoaffinity device secured to a peripheral box and connected to capillary electrophoresis or liquid chromatography for the isolation, enrichment, separation and identification of polymeric macromolecules, primarily protein biomarkers. In one embodiment, two devices are coupled in-tandem to perform separately and sequentially microreactions and concentrations of proteins. In this embodiment, biological samples containing proteins can be subjected to proteolytic processing in the first device, and the resulting peptides subjected to selective purification and concentration in the second device.

Abstract: The present invention reagents and methods for setting up an instruments having a multiplicity of detector channels for analyzing a multiplicity of fluorescent dyes. The present invention is particularly applicable in the field of flow cytometry.

Abstract: A luminescence detecting apparatus and method for analyzing luminescent samples is disclosed. A detecting apparatus may be configured so that light from luminescent samples pass through a collimator, a first lens, a filter, and a camera lens, whereupon an image is created by the optics on the charge-coupled device (CCD) camera. The detecting apparatus may further include central processing control of all operations, multiple wavelength filter wheel, and/or a robot for handling of samples and reagents.

Abstract: An apparatus for detecting an object capable of emitting light. The apparatus includes a light source and a waveguide. The waveguide includes a core layer and a first cladding layer. At least one nanowell is formed in at least the first cladding layer. The apparatus further includes a light detector. The light detector can detect a light emitted from a single molecule object contained in the at least one nanowell.

Abstract: Sensing compositions, sensing element, sensing systems and sensing devices for the detection and/or quantitation of one or more analytes. Compositions comprising carbon nanotubes in which the carbon nanotubes retain their ability to luminesce and in which that luminescence is rendered selectively sensitive to the presence of an analyte. Compositions comprising individually dispersed carbon nanotubes, which are electronically isolated from other carbon nanotubes, yet which are associated with chemical selective species, such as polymers, particularly biological polymers, for example proteins, which can interact selectively with, or more specifically selectivity bind to, an analyte of interest. Chemically selective species bind, preferably non-covalently, to the carbon nanotube and function to provide for analyte selectivity. Chemically selective species include polymers to which one or more chemically selective groups are covalently attached.

Abstract: Systems and methods are provided for sample processing. A device may be provided, capable of receiving the sample, and performing one or more of a sample preparation, sample assay, and detection step. The device may be capable of performing multiple assays. The device may comprise one or more modules that may be capable of performing one or more of a sample preparation, sample assay, and detection step. The device may be capable of performing the steps using a small volume of sample.

Abstract: Methods to produce pH-sensitive microparticles that have an active agent dispersed in a polymer matrix have certain advantages over microcapsules with an active agent encapsulated in an interior compartment/core inside of a polymer wall. The current invention relates to pH-sensitive microparticles that have a corrosion-detecting or corrosion-inhibiting active agent or active agents dispersed within a polymer matrix of the microparticles. The pH-sensitive microparticles can be used in various coating compositions on metal objects for corrosion detecting and/or inhibiting.

Abstract: The disclosure relates to a pixel-type biological analysis device comprising a photosensitive layer, a capture mixture for the capture of targeted proteins, the capture mixture being placed on an external surface of the photosensitive layer and comprising a protein probe grafted to a hydrogel, collection means for collecting photoelectrons in the photosensitive layer, and reading and treatment means of an electrical quantity supplied by the collection means, for the supply of a characteristic value of a luminous intensity detected by the photosensitive layer.

Abstract: The fluorescence measurement system includes a host apparatus and a self-contained, multichannel optical cartridge. The host apparatus includes a well plate receptacle, and a stage having optical cartridge receptacles that are elongate along one axis of the well plate. The stage and the well plate receptacle are movable relative to one another in the direction of the other axis of the well plate. The optical cartridge engages with the optical cartridge receptacle and includes a linear array of optical assemblies each including an excitation light source, and an emission light detector to generate an intensity signal. The optical cartridge also includes, a memory to store calibration information for each optical assembly. The host apparatus additionally includes a processor to correct the intensity signal from each optical assembly of the optical cartridge using the calibration information received from the optical cartridge for the optical assembly.