166 PATENT ABSTRACTS

bond-specific proteinases wilt therefore convert 4642169 the nonfluorescent bisamide derivative into a highly fluorescent monoamide derivative. C O N T I N U O U S R O T A T I N G

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

4640895

B I P H A S I C M E D I A C U L T U R E A P P A R A T U S

Sherman G Davis assigned to Gibco Division The Mogul Corporation

A one piece, biphasic media culture container, as disclosed herein, includes a first compartment for a solid nutrient culture medium, a second compartment for a liquid nutrient culture medium and a common headspace enclosure ab- ove and extending between said first and second compartments to provide selective fluid com- munication therebetween. The first and second compartments are discrete from one another ex- cept for the common headspace enclosure and are spatially separated by an air space between their respective inner walls.

Randall A Yoshisato, Ravindra Datta. Gregory R Carmichael assigned to University of Iowa Research Foundation

A continuous rotating annular electrophoresis column for the separation of chemical mixtures. The principle of separation is similar to the con- ventional electrophoresis; however, it is different in that the electric field is applied in the axial direction and the column is rotated. By rotating the column, the product path appears as helical bands, each with a characteristic, stationary exit point at some angular coordinate at the bottom of the column. By applying the electric field axially, the bed thickness can be kept thin for ef- fective heat transfer and temperature control. The apparatus can be used in the separations of biochemically active compounds, or to separate, based on the principal of charge, any chemical mixture. The column can also be packed with chromographic materials and thus operate as a electrochromographic separator.

4640898

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

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

T H E R E S P E C T I V E I N T E N S I T I E S O F B O U N D A N D F R E E L A B E L BY

S O L V E N T C O M P O N E N T S

Clarke Halfman assigned to University of Health Sciences/The Chicago Medical School

Fluorescence ligand binding assay of a sample containing an unknown amount of ligand may be performed by making direct intensity measurements, In an immunoassay, for ex- ample, the sample may be added to a solution containing fluorescein labeled analyte and then is added an antibody specific to the analyte. Sodium dodecyl sulfate, a surfactant, added to the solution in an amount sufficient to form micelles provides markedly different fluorescent intensity from bound and unbound labeled ana- lyte.

4642285

S A N D W I C H EIA F O R A N T I G E N

Seymour P Halbert, Milton Anken assigned to Diamedix Corporation

A sensitive direct immunoassay system is pro- vided for the detection of an antigen in body fluids. A single antibody which reacts with an antigen or antigens and which is bonded to an in- soluble member, is incubated with a test sample. During this first period of incubation a portion of an antigen present in the test sample will com- bine with the antibody immobilized on the in- soluble member. The antibody bonded member, to which antigen is attached, is then washed and incubated with an enzyme tagged antibody rea- gent. During the second incubation, the tagged antibody reacts with antigen fixed to the anti- body member in the first incubation. Thus, an immobilized £37 sandwich + 38 + 0 is formed of an insoluble member- antibody-antigen-enzyme tagged antibody. After the second incubation, the member is washed again to remove unreacted enzyme antibody reagent. The member is then exposed to a substrate which is converted by the enzyme to produce an end product. The tagged antibody reagent will be fixed in the second in-