PATENT ABSTRACTS 431

cessing steps, produces double-stranded linear A novel class of bioreactor apparatuses are dis- DNA molecules having an end containing a long closed which offer improved performance over target DNA segment that is susceptible to ex- prior art designs. The apparatuses circulate nutr- onuclease digestion and a sequencing p~'imer hi- ient fluid through a bioreactor device, such as a nding site end that is not susceptible to hollow fiber bioreactor cartridge, which is used ¢xonuclease digestion. Next, the target DNA to culture a colony of cells. The nutrient fluid is segment end is subjected to exonuclease diges- refreshed by the controlled addition of fresh tion. At timed intervals, portions of the ex- fluid and the controlled removal of used fluid onuclease digested linear double-stranded DNA through a sterile infusion/extraction device. Cel- molecules are removed. Since part of the target lular by-product yield is enhanced by DNA segment has been deleted by the ex- periodically alternating the direction of nutrient onuclease, the removed linear double-stranded fluid through the bioreactor and by periodically DNA molecules include shortened target DNA circulating the harvest fluid through the extra- segments. Next, the removed linear double- capillary region of the bioreactor cartridge. stranded DNA molecules are blunted and then recircularized to reform circular recombinant DNA molecules. The reformed recombinant DNA molecules are cloned to produce a plurality of circular DNA molecules containing shortened target DNA segments that differ in 4889922 length by the amount of target DNA that was removed by the exonuclease. The reformed cir- M O N O C L O N A L A N T I B O D Y cular DNA molecules are suitable for use in S P E C I F I C F O R H U M A N C O L O N , DNA sequencing other molecular manipula- F I B R O B L A S T - D E R I V E D T - P A tions of genetic material.

Jon Schaumann, Jitka Olander, Nicholaos K Hrakas, Joseph Feder assigned to Monsanto Co

4889801 A monoclonal antibody is disclosed which is specific for human colon fibroblast-derived tis-

3 A L P H A - H Y D R O X Y S T E R O I D sue plasminogen activator (t-PA), and which is O X I D A S E A N D Q U A N T I T A T I V E useful for immunoaffinity chromatography

A N A L Y S I S O F 3 A L P H A - purification of t-PA and determination of t-PA H Y D R O X Y S T E R O I D M A K I N G in a biological sample.

U S E O F S A M E

Koji Ushizawa, Tokyo, Japan assigned to Daiichi Pure Chemicals Co Ltd

4891137 Disclosed herein is a 3 alpha-hydroxysteroid ox- idase which oxidizes a 3 alpha-hydroxysteroid M E T H O D A N D A P P A R A T U S F O R into a 3-oxosteroid and hydrogen peroxide. The oxidase may preferably be obtained from a cul- M E M B R A N E E X T R A C T I O N O F ture broth of Pseudomonas testosteroni (ATCC H Y D R O L Y S I S C O N T A M I N A T E S 11996). The oxidase is useful for the quantitative analysis of a 3 alpha-hydroxysteroid. Method Andr Nohl, Ronald V Perkins assigned to and reagent useful for the quantitative analysis Spectra-Physics Inc of a 3 alpha-hydroxysteroid are also disclosed.

A process removes FMOC-OH which is an un- desirable by-product of the derivatization of amino acids by FMOC. The process uses a silicone rubber membrane extractor cell. The

4889812 sample containing the FMOC-OH is held in a silicone rubber tubing, while pentan¢ flows past

B I O R E A C T O R A P P A R A T U S the outside of the tube; the FMOC-OH is thus extracted from the sample into the pentane. The

Perry W Guinn, Gary N Mills, Robert A Bed- process is integrated into a conventional high ient, Martin O Greeley assigned to C D Medical performance liquid chromatography system and Inc is readily automated.