4889799 Reagent kit producing shortened target DNA segments usable in sequencing large DNA segments

NEW PATENTS This Section contains abstracts and, where appropriate, illustrations of recently issued United States patents and published patent applications filed from over 30 countries under the Patent Cooperation Treaty. This information was obtained from recent additions to the Pergamon PATSEARCHs online database in accordance with interest profiles developed by the Editors. Further information about Pergamon PATSEARCHs can be obtained from Pergamon Orbit InfoLine Inc., 8000 Westpark Drive, McLean, Virginia 22102, U.S.A. Copies of complete patents announced in this Section are available from Pergamon Orbit InfoLine Inc. for $8 per copy. Payment with order is required. Orders outside North America add $2 for air postage. Order by patent number for Pergamon Orbit lnfoLine only.

Mutation/Genetic Engineering Techniques 4889799

onuclease digested linear double-stranded DNA molecules are removed. Since part of the target DNA segment has been deleted by the exonuclease, the removed linear double-stranded DNA molecules include shortened target DNA segments. Next, the removed linear doublestranded 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 length by the amount of target DNA that was removed by the exonuclease. The reformed circular DNA molecules are suitable for use in DNA sequencing other molecular manipulations of genetic material.

REAGENT KIT PRODUCING SHORTENED TARGET DNA SEGMENTS USABLE IN SEQUENCING LARGE DNA SEGMENTS Steven Henikoff, Richard E Gelinas assigned to Fred Hutchinson Cancer Research Center A process is provided for producing an ordered series of cloned, circular, DNA molecules containing shortened target DNA segments derived from a long target DNA segment, which are suitable for use in determining the nucleotide sequence of the long target DNA segment, or for targeting specific regions within the target DNA segment. The process includes producing, by molecular cloning, a plurality of doublestranded recombinant DNA molecules each containing: (i) vector DNA; (ii) a sequencing primer binding site; and, (iii) a DNA region having unique endonuclease sites and a long target DNA segment. The sequencing primer binding site is spaced from the long target DNA segment by at least a portion of said DNA region having the unique endonuclease sites. The plurality of double-stranded circular recombinant DNA molecules are cleared using two restriction endonucleases. The cleavage occurs in the portion of the DNA having unique endonuclease sites lying between the long target DNA segment and the sequencing primer binding site. The cleavage and, if necessary, subsequent processing steps, produces double-stranded linear DNA molecules having an end containing a long target DNA segment that is susceptible to exonuclease digestion and a sequencing primer binding site end that is not susceptible to exonuclease digestion. Next, the target DNA segment end is subjected to exonuclease digestion. At timed intervals, portions of the ex-

4~9802 ENHANCED PRODUCTION OF RECOMBINANT PROTEINS IN MYELOMA CELLS Tristram Parslow, Keith R Yamamoto assigned to The Regents of the University of California A mammalian myeloma cell comprising a double-stranded DNA molecule in its genome containing a coding sequence encoding a nonimmunoglobulin protein, a nonimmunoglobulin promoter sequence adjacent to the 5' terminus of said coding sequence, and the 8-base pair nucleotide sequence 5'ATTTGCAT-3' located 5' to the transcription initiation site of said promoter sequence. The DNA molecule may optionally contain an enhancer element. Methods of producing nonimmunoglobulin protein and D N A molecules are also provided. 583