PATENT ABSTRACTS

4990441

P R O C E S S F O R S E P A R A T I N G 2 - K E T O - L - G U L O N I C A C I D F R O M

A F E R M E N T E D M E D I U M

Jean-Pierre Barthole, Jean Filippi, Aurelia Jaeger-Seddik, Isidore Le Fur, Jean-Yves Pom- mier, Elbeuf, France assigned to Rhone-Poulenc Sante

2-Keto-L-gulonic acid is separated from a fer- mented medium containing the calcium salt of 2- keto-L-gulonic acid, by carrying out the following operations: separation of insolubles: removal of inorganic cations; and separation of the 2-keto-L-gulonic acid.

4990442

A S S A Y F O R AN A N A L Y T E O N A S O L I D P O R O U S S U P P O R T

Campo G B Del, Milan, Italy assigned to Chem- etron

An assay for an analyte wherein sample is applied to a support capable of binding proteins by essentially only hydrogen bonding and fixed on the support. Analyte may be determined on the support by use of a suitable tracer. A pre- ferred support is amphiphilic cellulose acetate. In an immunoassay, it is possible to determine analyte without use of a supported ( capture ) antibody.

4990443

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

I M M U N O A S S A Y S

Erasmus Huber, Christian Klein, Gunter Pap- pert, Klaus Hallermayer, Garching. Federal Republic Of Germany assigned to Boehringer Mannhcim GmbH

The present invention provides hapten derivatives of the general formula: See Patent for Chemical Structure (I) wherein Hap is a residue formed from a hapten carrying a keto or al- dehyde group by splitting off an oxo group and RI and R2, which can be the same or different. are alkyl radicals containing up to 7 carbon atoms and one of the symbols R1 and R2 can also represent a hydrogen atom. The present in-

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vention also provides hapten-protein conjugates of the general formula: See Patent for Chemical Structure (III) wherein Hap, R 1 and R2 have the above-given meanings and E-NH is the residue of a protein bound via an epsilon-amino group of a lysine residue.

4990444

G A M M A - G L U T A M Y L T R A N S P E P T I D A S E , I T S

P R E P A R A T I O N A N D I T S U S E

Werner Aretz, Klaus Sauber, Kfederal Republic Of Germana assigned to Hoechst Aktiengesel- lschaft

It is possible with the aid of a gamma-glutamyl transpeptidase, which can be prepared by fer- mentation, to hydrolyze adipinyl- or glutaryl- monoamino compounds, in particular alpha- keto-adipinyl- or glutaryl-7- aminocephalosporani c acid.

4990445

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

Sandra M Poudrier, Mark T Oyen assigned to Beckman Instruments Inc

A stable reagent and kinetic assay for alpha- amylase is provided. The reagent comprises a substrate for the alpha-amylase and various en- zymes and cofactors necessary to produce NADH as the end-product of a series of four reactions. The substrate, enzymes, and cofactors are provided in sufficient excess that the alpha- amylase from the test sample is the rate-limiting factor. The concentration of alpha-amylase in a test sample is determined by measuring the rate of increase in absorbance caused by the produc- tion of NADH. The use of the novel cofactor fructose-l, 6-diphosphate has been found to im- part improved stability to the reagent.

4990447

P R O C E S S F O R T H E P U R I F I C A T I O N O F S E R U M

A L B U M I N

Boudewijn W Konig. Michiel Hamers, Laken Cornelis van der, Amsterdam, Netherlands as- signed to Gist-Brocades NV