428 PATENT ABSTRACTS

4885240

U S E O F O R G A N I C B U F F E R S T O R E D U C E D E H Y D R O A S C O R B I C

A C I D I N T E R F E R E N C E I N A N A L Y T I C A L M E T H O D S

Annie Wu assigned to Eastman Kodak Com- pany

The interference of dehydroascorbic acid, an ox- idation product of ascorbic acid, in analytical methods is reduced with the use of certain nitrogen-containing organic buffers. Dehy- droascorbic acid tends to cause premature reduction of reducible compounds which are used to provide detectable species in the presence of an analyte. These organic buffers, as opposed to inorganic buffers, prevent premature reduc- tion of the reducible compounds. An analytical method can be carried out in solution or in a dry analytical element.

4886602

P R O C E S S F O R T H E S E P A R A T I O N O F B I O T E C H N O L O G I C A L L Y

P R O D U C E D V A L U A B L E M A T E R I A L S F R O M A

F E R M E N T E R B R O T H BY C R O S S F L O W M I C R O - A N D / O R

U L T R A F I L T R A T I O N

Norbert Kuehne, Wilfried Raehse, Franz-Josef Carduck, Haan, Federal Republic Of Germany assigned to Henkel Kommanditgesellschaft auf Aktien

The invention is a process for the separation of biotechnologicaUy produced valuable materials from a fermenter broth by crossflow microfiltra- tion and/or ultrafiltration, in which at least two modules arranged in series and fitted with porous membranes are used per stage, to pro- duce concentrate and a permeate which contains the valuable material. The pressure of the per- meate is controlled so that the absolute pressure on the permeate side is at different absolute pre- ssure in each module.

4885253

U N I V E R S A L B I O L O G I C A L I N D I C A T O R S Y S T E M

Raymond C Kralovic assigned to Steris Cor- poration

A cylindrical, transparent capsule (10) is less than half filled with a liquid culture medium (12). An open end of the capsule is closed by suppor- ting annulus (24) and a vent tube (28) having a vent aperture (30) at a free end thereof. The vent aperture is disposed at a volumetric center of the capsule such that an upper surface of the liquid culture medium is disposed below the vent aper- ture in any orientation of the capsule (FIG. 2). A heat labile membrane (32) which becomes porous in the presence of steam seals the.vent passage but provided a pressure escape from the capsul~ at steam sterilizing temperatures. A disk inoculated with microorganisms is supported by the annular support. A cap (40) is slidably movable between a first position (FIG. 1) in which apertures (42) provide a liquid flow path between the inoculated disk and the exterior and a second position (FIG. 3) in which a severing ring (46) severs the support a~nulus bringing the inoculated disk and the culture medium into contact (FIG. 4).

4886744

F L U O R E S C E N T C O N J U G A T E S A N D B I O L O G I C A L D I A G N O S T I C

A S S A Y S Y S T E M

Michael Arnost, Shai Inbar, Frank Meneghini, Paul S Palumbo, Stephen Stroud, Charles M Zepp assigned to Polaroid Corporation

Fluorescent compounds which are conjugates of a biologically active moiety and an arylidene dye moiety. The compounds have a large Stokes shift and are useful in applications such as biological diagnostic elements.

4886755

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

A C T I V E L I G A N D S

That T Ngo assigned to Bioprobe International Inc

Thiol gels are prepared from hydroxyl con- taining polymers by forming a 2-fluoro-1- methylpyridoxy derivative of the polymer