PATENT

into a cavity in the pump housing, The osmotic fluid pump forces its pre-charged contents, i.e. the cell culture medium or nutrient, through an inlet passage into the cell culture chamber. The exhausted or expanded cell culture medium or nutrient can drain or exhaust through an outlet passage into the cavity of the pump housing. This ensures that no excess pressures arise in the system. The apparatus is especially well-suited for carrying out or implementing biological ex- periments under zero gravity conditions such as prevail in spaceships. The process transpires automatically and without supplementary inter- vention by astronauts. Even in terrestrial laboratories, the apparatus is especially well- suited for carrying out or performing experi- ments in the areas of developmental biology and embriology, since nutrients or other substances must often be continuously supplied in these fields.

4680267

F E R M E N T O R C O N T R O L S Y S T E M

Lee Eppstein, Robert D Mohler, Shaul Reuveny assigned to New Brunswick Scientific Company Inc

A method and an apparatus for controlling the concentration of oxygen and pH of a medium during a bioreaction process in a vessel. The method and apparatus are particularly adapted to a fermentation process. A dissolved oxygen sensor generates a signal corresponding to the pH of the medium and a dissolved oxygen sensor generates a signal corresponding to the dissolved oxygen in the medium. A valve mechanism selec- tively applies air, N2, 02 and CO2 to the medium. A controller produces a control signal for controlling the operation of the valve means so that a substantially fixed volume of gas con- sisting of one or more of air, CO2, N2 and 02 are added to the fermenting medium during a period of time. The controller determines in response to the dissolved oxygen and pH signals, the amount of CO2, O2 and/or N2 required to effect dis- solved oxygen and pH correction. The controller further adjusts these determined values to com- pensate for the displacement of the CO2 added. As a result, the effect of the CO2 correction on the dissolved oxygen is substantially minimized.

ABSTRACTS

4680268

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I M P L A N T A B L E G A ~ C O N T A I N I N G B I O S E N S O R A N D M E T H O D F O R M E A S U R I N G A N A N A L Y T E S U C H AS G L U C O S E

Leland Clark assigned to Children£3 s Hospital Medical Center

The present invention relates to a novel im- plantable biosensor and method for sensing pro- ducts, such as hydrogen peroxide, generated from an enzymatic reaction between an analyte, like glucose, and an enzyme in the presence of oxygen. The novel implantable biosensor is uni- quely equipped with an enclosed chamber for containing oxygen and can be adapted for extra- cting oxygen from animal tissue adjacent the container. The reservoir of oxygen contained in the enclosed chamber is supplied to the en- zymatic reaction from the side of the membrane opposite the enzyme. The enclosed chamber is uniquely designed to be impermeable to sub- stances, like liquid and cells, that possibly can interfere with the supply of the oxygen per- meating through the membrane to the enzymatic reaction. Also, the implantable biosensor is designed to optically or electrically sense pro- ducts generated from the enzymatic reaction which serve as a function of the analyte.

4680269

M E T H O D A N D A P P A R A T U S F O R P R E V E N T I N G C R O S S - C O N T A M I N A T I O N O F

B I O C H E M I C A L T E S T W E L L S I N A M I C R O T I T E R T E S T P L A T E

Harry B Naylor assigned to Pasco Laboratories lnc

This invention relates to a porous barrier im- pregnated with an acidic compound positioned in overlying relation atop the biochemical test wells portion of an antibiotic microtiter test plate effective to intercept and neutralize volatile alkaline products evolved through bacterial growth taking place therein before they can dif- fuse and contaminate nearby test wells and pro- duce erroneous pH-sensitive color tests. The invention also relates to an improved method for preventing cross-contamination of the bio- chemical tests being carried out in test wells adja- cent microtiter test wells, the contents of which are being analyzed for antibacterial activity.