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4948731 Modified transcriptionally active SP6 plasmid vector
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PATENT ABSTRACTS
pressed from the cell to reduce the exonuclease activity associated with the T7-type DNA polymerase compared to the level of exonuclease activity associated with a corresponding naturallyoccurring T7-type DNA
4946798 SEMICONDUCTOR INTEGRATED CIRCUIT FABRICATION METHOD Akira Kawakatsu, Tokyo, Japan assigned to Oki Electric Industry Co Ltd In a semiconductor integrated circuit fabrication method, isolated regions are in a silicon substrate, which is then covered with polysilicon, a passive base region is then formed, the polysilicon is selectively oxidized, the unoxidized polysilicon is then doped at first and second concentrations, a surface insulating layer is then deposited, the dopant is then diffused from the polysilicon to create further passive and active base regions, contact holes are then opened, the polysilicon above the active base is then doped, and this dopant is then diffused to create an emitter region in the active base. By employing a polysilicon layer with reduced initial thickness, this fabrication method enables precise doping with excellent control over the active base concentration, junction depth, polysilicon sheet resistance, and other parameters. It also enables the base junction depth to be reduced and the eptitaxial layer to be made thinner than before, leading to a high gain-bandwidth product, high switching speed, and generally reduced device dimensions.
4948731 MODIFIED TRANSCRIPTIONALLY ACTIVE SP6 PLASMID VECTOR Lee Gehrke, Robert T Fraley, Stephen G Rogers assigned to Massachusetts Institute of Technology A recombinant plasmid which may be used for propagation of cloned cDNAs and also for the in vitro synthesis of RNA which is an exact copy of the natural sequence, wherein the transcript is devoid of vector-derived sequence. The novel vector was generated de novo by genetic engineering procedures using a synthetic double strand oligodeoxyribonucleotide fragment and a
larger DNA fragment derived from plasmid pSP64. The vector, plasmid pHST-O, carried by Escherichia coil HB101, deposited with the ATCC on Dec. 30, 1985 and designated ATCC 53381, is distinguished from other vectors containing the SP6 promoter by the following characteristics: it contains a unique site for the restriction endonuclease BglII; the engineered GBIII site overlaps the downstream border of the SP6 promoter sequence; and the presence and positioning of the BglII restriction site permit insertion of cDNA molecules in such a way that transcription by the SP6 RNA polymerase begins exactly at the 5' terminus of the RNA, providing that the 5' terminal nucleotide of the mRNA transcript is a guanosine (G) residue, thus excluding the transcription of nucleotides derived from the vector. The novel vector permits synthesis of RNA molecules which have a defined 5' terminus and which are devoid of vector-derived sequence. The vector has potential use in research in molecular biology and in the in vitro production of RNA and proteins.
4948733 ZOOGLOEA TRANSFORMATION USING EXOPOLY SACCHARIDE NON-CAPSULE PRODUCING STRAINS Donald D Easson, Oliver Peoples, Anthony J Sinskey assigned to Massachusetts Institute of Technology Two new bacterial strains designated Zoogloea ramigera 115SL and Zoogloea ramigera ll5SLR, a rifampicin resistant derivative of 115SL, have been developed. These strains are derived from the wild type Zoogloea ramigera 115, ATCC 25935. The two new strains produce a novel exopolysaccharide (EPS) and have several desirable characteristics that are absent from the parent strain, including improved culture properties, since they do not produce an EPS capsule layer like that of the parent 115 strain. The 115SL EPS is instead excreted as a slime layer which is not confined to the immediate area surrounding the cells. Since cells are not trapped within a floc where they grow at a reduced rate or die because of nutrient starvation, the new strains have more consistent and reproducible growth cycles and increased growth rates. As a consequence, exopolysaccharide production is more consistent and titers are higher. The separation of the EPS from the cells is also much easier and more economical. The other very important charac-
PATENT ABSTRACTS
pressed from the cell to reduce the exonuclease activity associated with the T7-type DNA polymerase compared to the level of exonuclease activity associated with a corresponding naturallyoccurring T7-type DNA
4946798 SEMICONDUCTOR INTEGRATED CIRCUIT FABRICATION METHOD Akira Kawakatsu, Tokyo, Japan assigned to Oki Electric Industry Co Ltd In a semiconductor integrated circuit fabrication method, isolated regions are in a silicon substrate, which is then covered with polysilicon, a passive base region is then formed, the polysilicon is selectively oxidized, the unoxidized polysilicon is then doped at first and second concentrations, a surface insulating layer is then deposited, the dopant is then diffused from the polysilicon to create further passive and active base regions, contact holes are then opened, the polysilicon above the active base is then doped, and this dopant is then diffused to create an emitter region in the active base. By employing a polysilicon layer with reduced initial thickness, this fabrication method enables precise doping with excellent control over the active base concentration, junction depth, polysilicon sheet resistance, and other parameters. It also enables the base junction depth to be reduced and the eptitaxial layer to be made thinner than before, leading to a high gain-bandwidth product, high switching speed, and generally reduced device dimensions.
4948731 MODIFIED TRANSCRIPTIONALLY ACTIVE SP6 PLASMID VECTOR Lee Gehrke, Robert T Fraley, Stephen G Rogers assigned to Massachusetts Institute of Technology A recombinant plasmid which may be used for propagation of cloned cDNAs and also for the in vitro synthesis of RNA which is an exact copy of the natural sequence, wherein the transcript is devoid of vector-derived sequence. The novel vector was generated de novo by genetic engineering procedures using a synthetic double strand oligodeoxyribonucleotide fragment and a
larger DNA fragment derived from plasmid pSP64. The vector, plasmid pHST-O, carried by Escherichia coil HB101, deposited with the ATCC on Dec. 30, 1985 and designated ATCC 53381, is distinguished from other vectors containing the SP6 promoter by the following characteristics: it contains a unique site for the restriction endonuclease BglII; the engineered GBIII site overlaps the downstream border of the SP6 promoter sequence; and the presence and positioning of the BglII restriction site permit insertion of cDNA molecules in such a way that transcription by the SP6 RNA polymerase begins exactly at the 5' terminus of the RNA, providing that the 5' terminal nucleotide of the mRNA transcript is a guanosine (G) residue, thus excluding the transcription of nucleotides derived from the vector. The novel vector permits synthesis of RNA molecules which have a defined 5' terminus and which are devoid of vector-derived sequence. The vector has potential use in research in molecular biology and in the in vitro production of RNA and proteins.
4948733 ZOOGLOEA TRANSFORMATION USING EXOPOLY SACCHARIDE NON-CAPSULE PRODUCING STRAINS Donald D Easson, Oliver Peoples, Anthony J Sinskey assigned to Massachusetts Institute of Technology Two new bacterial strains designated Zoogloea ramigera 115SL and Zoogloea ramigera ll5SLR, a rifampicin resistant derivative of 115SL, have been developed. These strains are derived from the wild type Zoogloea ramigera 115, ATCC 25935. The two new strains produce a novel exopolysaccharide (EPS) and have several desirable characteristics that are absent from the parent strain, including improved culture properties, since they do not produce an EPS capsule layer like that of the parent 115 strain. The 115SL EPS is instead excreted as a slime layer which is not confined to the immediate area surrounding the cells. Since cells are not trapped within a floc where they grow at a reduced rate or die because of nutrient starvation, the new strains have more consistent and reproducible growth cycles and increased growth rates. As a consequence, exopolysaccharide production is more consistent and titers are higher. The separation of the EPS from the cells is also much easier and more economical. The other very important charac-