PATENT ABSTRACTS

growth of mammalian cells, comprising in- cubating the cells with a biologically active PDGF analog expressed by a eucaryotic host cell transformed with such a DNA construct, are also disclosed.

4766075

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

David Goeddel, William Kohr, Diane Pennica, Gordon Vehar assigned to Genentech lnc

Human tissue phasminogen activator (t-PA) is produced in useful quantities using recombinant DNA techniques. The invention disclosed thus enables the production of t-PA free of con- taminants with which it is ordinarily associated in its native cellular environment. Methods, ex- pression vehicles and various host cells useful in its production are also disclosed.

4766077

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

M A N I P U L A T I O N

Cindy Orser, Steve Lindow, Nickolas Panapoulos assigned to The Regents of the University of California

Ice nucleation bacteria are modified in vitro to confer an ice nucleation deficient phenotype. Modification is accomplished by deletion, sub- stitution, insertion, inversion, or transversion of a DNA segment within the gene locus responsible for the INA phenotype. By limiting such mutations to the particular gene locus, the modified microorganisms are genetically stable and free from random mutations which might adversely affect their competitive fitness. The modified microorganisms are useful for preven- tion of frost damage to susceptible plant hosts.

4 7 ~ 6 ~

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

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

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

D E T E C T I O N

Calvin P H Vary, Steven E Diamond, Neil Wolf- man assigned to Allied Corporation

65

A reagent complex is disclosed containing (1) a probe polynucleotide having a target binding re- gion complementary to a target nucleotide sequence and (2) a signal strand polynucleotide bound by base pairing to a portion of the target binding region. The signal strand is displaced from the reagent complex by the target nucleotide sequence and separated from intact reagent complexes. A digestable ribonucleotide segment of the displaced signal strand, such as a 3" terminal segment, is digested to ribonucleotide phosphates, which are phosphorylated to ATP. The ribonucleotide phosphates or ATP are detected.

4767700

D E T E C T I O N O F P A R T I C U L A R N U C L E O T I D E S E Q U E N C E S

R Bruce Wallace, Freiburg, Federal Republic Of Germany assigned to Beckman Research In- stitute of the City of Hope

A process for the detection of a particular poly- nucleotide sequence in a polynucleotide- containing test sample comprising forming an agarose gel having a depression therein, adding the test sample to said depression, putting agarose solution in the depression and permit- ting it to gel thereby to encase the test sample in agarose gel, denaturing the polynucleotide in the test sample within the agarose gel, under hybridization conditions contacting the test sample-containing gel with an oligonucleotide or polynucleotide probe having a sequence comple- mentary with a sequence for which the sample is being tested, and determining the extent of hybridization.

4767708

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

Edwin Minkley, William E Brown assigned to Carnegie Mellon University

Restriction enzymes are used to remove from DNA a complete and undamaged structural gene coding region for the expression of DNA polymerase I (polA) without the gene's natural promoter or with only a significantly damaged portion of the gene's natural promoter. Also by the use of restriction enzymes, a segment from a plasmid cloning vector is excised at a position adjacent to a promoter which is conditionally