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: An apparatus and method for the detection of the growth of microorganisms through infrared analysis of a sample of the gas produced by growth of the microorganism is descirbed. In the method, a sample of the headspace gas in a vial containing a growth medium which has been inoculated with a sample suspected of containing a microorganism is removed and transferred to a sample cell where infrared analysis is used to determine the presence of carbon dioxide, if any, produced by the growth of the microorganism.

Abstract: Reliable and rapid detection of microorganisms is accomplished in an electroanalytical cell using a pulsed voltammetric detection technique employing the growth medium as the electrolyte and analyte and using simple wire electrodes fabricated from readily available materials. Organism detection occurs as a consequence of the depletion of oxygen in the growth medium/electrolyte caused by aerobic metabolism. Times-to-detection vary with inoculum strength in a predictable fashion, permitting quantification of the organism in question when results are compared to those obtained using known inocula of the same organism. The low duty cycle of the pulsed measurement enables the determination of the relative redox potential in the same cell using the same set of electrodes in order to provide information which may be characteristic of the type of organism being studied.

Abstract: The detection of "significant bacteriuria" in a urine sample is accomplished by measuring the head space gas oxygen consumption in a closed vial system. A sample to be tested is introduced into a sealed vial containing a growth medium and the head space gas oxygen concentration initially measured. After a suitable incubation period, the oxygen concentration above the sample is again measured using a closed sample loop. A decrease in the head space oxygen concentration below a predetermined level indicates the presence of a significant quantity of oxygen consuming microorganisms in the sample.

Abstract: A sample of material to be tested for the presence of biologically active agents, such as bacteria, is introduced into a sealable container partially filled with a culture medium comprising a .sup.13 C-labeled fermentable substrate, the remainder of the container being filled with a culture gas, the container and its contents are subjected to conditions conducive to biological activity for a predetermined period sufficient for fermentation of the medium to produce carbon dioxide after which the ratio of .sup.13 CO.sub.2 to .sup.12 CO.sub.2 in the culture gas in the container is determined and compared to the initial ratio of .sup.13 CO.sub.2 to .sup.12 CO.sub.2 in the culture gas in order to detect any differences indicating the presence of biologically active agents in the sample.

Abstract: A sample of material to be tested for the presence of oxygen consuming bacteria is introduced into a sealable container partially filled with a culture medium; the remainder of the container being filled with an oxygen containing gas, the container being connected to means for sensing the production of a vacuum therein. The container and its contents are subjected to conditions conducive to bacterial growth for a predetermined period sufficient for growth of bacteria to consume some of the oxygen, during which time the pressure of the gas in the container is monitored and compared to the initial pressure in order to detect the production of a vacuum due to consumption of oxygen by bacteria from the test sample, thereby indicating the presence or absence of oxygen consuming bacteria in the sample of test material.

Abstract: A sample of material to be tested for the presence of biologically active agents, such as bacteria, is introduced into a sealable container partially filled with a culture medium; the remainder of the container being filled with a culture gas, the container and its contents are subjected to conditions conducive to biological activity for a predetermined period sufficient for fermentation of the medium to produce at least one gaseous product after which the character of the culture gas in the container is determined and compared to the initial character of the culture gas in order to detect any differences caused by changes in the composition of the culture gas indicating the presence or absence of biologically active agents in the sample.