310

4554254

PATENT ABSTRACTS

P R O T E I N A S S A Y BY S I L V E R B I N D I N G

Gerald Krystal, Vancouver, B C, Canadd

A novel, inexpensive, highly sensitive and quan- titative assay for measuring protein in solution based on the capacity of protein to bind silver is described. In this procedure, protein samples are first treated with glutaraldehyde and then ex- posed to ammoniacal silver. After a specified time, the reaction is terminated by the addition of sodium thiosulfate and the optical density measured at 420 nm. The useful range of the as- say for the majority of standard proteins tested lies between 15 and 2000 ng. This represents a 100-fold increase in sensitivity over the Coomas- sie Brilliant Blue dye binding procedure. There is little or no interference from carbohydrates, non-ionic detergents or ethanol. Pretreatment of protein samples with Bio-Gel P-2 to remove salts, thiol agents, EDTA and SDS, makes this procedure compatible with most commonly used buffers.

4555490

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

Carl Merril assigned to The United States of America as represented by the Department of Health and Human Services

A method using light ( photodevelopment ) to develop a metallic silver image of biopolymers, particularly nucleic acids and proteins separated on polyacrylamide gels, whereby it is possible to visualize protein and nucleic acid patterns within l0 minutes after electrophoretic separation. This photodevelopment method requires only two solutions: a solution to fix the proteins and a solution containing silver ions, which produces an image when exposed to light. This type of pro- tein stain has achieved a sensitivity of about 0.5 ng of protein. DNA separated on poly- acrylamide may also be visualized with this stain.

4556635

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

O R G A N I C S Y S T E M S

Donald Hitzman, Thomas Hopkins assigned to Phillips Petroleum Company

The concentration ofa Ci to C4 alcohol in an es- sentially water immiscible organic system is ac- curately determined by a simple and quick process. A sample of the water immiscible or- ganic system containing less than about 0.01?,~ (W/V) of the alcohol is contacted with an aqueous layer of alcohol oxidase immobilized on an electrode for measuring dissolved oxygen content. Ethanol in the water immiscible organic system partitions into the aqueous layer where alcohol oxidasc catalyzes oxidation of the alcohol. Oxygen consumed during the oxidation is measured by the electrode, and the concentra- tion of alcohol determined therefrom. To obtain less than about 0.01% alcohol in the sample, the sample may be diluted with the water immiscible organic system.

4556636

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

T H E D E T E C T I O N O F B A C T E R I A

Robert T Belly, Laurie J Clements assigned to Eastman Kodak Company

A composition, an analytical element and a method for the detection of bacteria in specimen samples, e.g. biological fluids, are disclosed. The composition optionally, but preferably, com- prises a metabolizable substrate (e.g. glucose) and a benzindole dye which undergoes a detec- table color change when incubated in admixture with a bacterial microorganism. Useful dyes in- clude particular benz(cd)indole, benz(e)indole and benz(g)indole compounds. The described analytical element contains this composition, preferably, in a spreading zone. Detection of bacteria can be accomplished by bringing the composition or element into contact with a specimen sample. This invention is particularly useful in detection of significant bacteriuria.

4556639

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

Masao Izawa, Sachiko Tatsukawa, Tokyo, Japan assigned to Olympus Optical Co Ltd

A method for dislodging cultured cells has the steps of preparing a culture container which has a growing surface on which cultured cells are grown, and which is filled with a culture solution in contact with the cultured cells, supporting the