Abstract: Apparatus is disclosed for controlling the heating and cooling of a plurality of upright containers containing a mixture used for performing gene amplification. The apparatus includes a support rack comprising aluminum blocks which is partially submerged in a thermally conductive fluid such that at least the lower portions of the containers are submerged in the fluid with the upper portions engaging the aluminum blocks for efficient heat transfer. Heaters are disposed within the aluminum block for heating the block and a plurality of thermoelectric cooling cells are used to cool the block. A programmable microprocessor is used for controlling the heating and cooling cycles, thereby allowing repetitive heating and cooling of the mixture to produce the copies of the genetic material sought to be copied. A cam separates the support rack from the cooling cells during the heating portion of the process.

Abstract: An oxygen detector for detecting the presence of trace levels of oxygen in an anaerobic environment consisting of a sample chamber wherein a sample from the anaerobic environment is exposed to a catalyst, such as palladium, which promotes the exothermic chemical reaction of oxygen with hydrogen. The presence of oxygen will cause such reaction to occur on the catalyst and the consequent generation of heat. A thermistor which is in thermal proximity to the catalyst detects this heat and provides a signal. The sampling chamber is enclosed by an enclosure which serves to volumetrically and thermally confine the sample during the measurement thereby enabling small levels of exothermic heat of reaction to be detected. Entrance to the sampling chamber is through a membrane which is permeable to lower molecular weight gases such as oxygen and hydrogen which thus enables diffusion of the anaerobic atmosphere into the chamber.

Abstract: A gas analyzer for performing gas analysis on a sample gas containing contaminants which normally interfere with the operation of the analyzer is disclosed comprising a source of radiant energy; means for directing radiant energy through a sample gas; a disposable gas cell; a detector for receiving radiant energy; and a circuit for analyzing the output of the detector and indicating the concentration of predetermined constituents in the sample gas. The gas cell comprises a disposable sample gas cell having a sample enclosure for containing a sample gas volume; sample windows defining a portion of a sample gas optical path extending from the source of radiant energy through the sample gas volume to the detector; an inlet for supplying sample gas to the sample gas volume and an outlet for exhausting sample gas from the sample gas volume.