摘要:
A disposable pipette tip (10) is formed for automatic installation and removal with low friction between the tip and pipette body (16) and a predetermined distance from the pipette body end (19) and the tip intake/discharge opening (12). The tip has a conical section (11) whose small end defines the tip intake/discharge opening and a cylindrical collar (14) that receives the pipette body. The tip is formed with an internal pipette seat (17) at the junction of the conical section and cylindrical collar so that the distance between the tip inlet/discharge opening and the pipette body end is fixed. The cylindrical collar also has a circumferential sealing rib (30) axially spaced from the pipette seat to form an air seal to account for manufacturing tolerances in the tip's cylindrical portion as to both diameter and roundness while maintaining low friction for installation and removal.
摘要:
Described are monoclonal antibodies having conformation-dependent specificity for native dsDNA, as exemplified by the IgM antibody produced by murine hybridoma ATCC No. HB 8329, have been prepared. These antibodies may be bound to double-stranded DNA to form immune complexes and thus are useful in immunodiagnostic tests to detect DNA duplex formation by DNA hybridization and to separate dsDNA from a solution containing it.
摘要:
The invention provides muteins of biologically active proteins such as IFN-B and IL-2 in which cysteine residues that are not essential to biological activity have been deleted or replaced with other amino acids to eliminate sites for intermolecular crosslinking or incorrect intramolecular disulfide bridge formation. These muteins may be made via bacterial expression of mutant genes that encode the muteins and have been synthesized from the genes for the parent proteins by oligonucleotide-directed mutagenesis.
摘要:
A process for producing wax esters having the general structural formula RCO 2 R', where R and R' are radicals selected from the group consisting of CH 3 (CH 2 ) a CH=CH(CH 2 ) b - and CH 3 (CH 2 ) c - where a + b = 12-14 for R and 13-15 for R' and where c = 14-16 for R and 15-17 for R'. The method includes aerobically incubating a culture of microorganisms of the genus Acinetobacter species HOI-N, in an aqueous mineral salts solution containing ethanol as a primary food source. Incubation is performed at a temperature known to produce a desired percentage of diene, monoene and saturated R and R' moieties in the mixture.
摘要:
New polypeptide, called IFN- alpha 74, produced by E.coli transformed with a newly isolated and characterized human IFN- alpha gene. The polypeptide exhibits interferon activities such as antiviral activity, cell growth regulation, and regulation of production of cell-produced substances.
摘要:
A new polypeptide, called IFN- alpha 61, produced by E. coli transformed with a newly isolated and characterized human IFN- alpha gene is described. The polypeptide exhibits interferon activities such as antiviral activity, cell growth regulation, and regulation of production of cell-produced substances.
摘要:
The invention provides plasmids of ColEl type parentage which have a temperature sensitive replication system such that the plasmid copy number in a given host cell may be controlled by a temperature shift. Such plasmids permit the use of temperature as a switch for controlling gene amplification and hence the production of corresponding protein in a host cell.
摘要:
The problem of producing stable DNA plasmids of high copy number may be solved by selecting mutants in which an altered repressor gene leads to high copy number replication. The plasmids are modifed by placing a suitable transcriptional "stop" signal after an inserted heterogenous gene so that the readthrough expression of the heterologous DNA will not continue into the replication primer strand. Deletions resulting from interference with replication primer strand transcription are thereby avoided. Such plasmids may be used to produce a desired protein by introducing them into a host microorganism and allowing the host to express phenotypically its genotype (including the plasmids).
摘要:
HLA typing based on restriction length polymorphism is carried out by: digesting an individual's HLA DNA with a restriction endonuclease that produces a polymorphic digestion pattern with HLA DNA; subjecting the digest to genomic blotting using a labeled cDNA hybridization probe that is complementary to an HLA DNA sequence involved in the polymorphism; and comparing the resulting genomic blotting pattern with a standard This technique may be adapted to make paternity or transplant or transfusion compatibility determinations or to make disease association correlations to diagnose diseases or predict susceptibility to diseases. Locus specific cDNA hybridization probes, particularly probes for genes of Class II loci (D and OR loci), for use in the typing procedure are described.
摘要:
HLA typing based on restriction length polymorphism is carried out by: digesting an individual's HLA DNA with a restriction endonuclease that produces a polymorphic digestion pattern with HLA DNA; subjecting the digest to genomic blotting using a labeled cDNA hybridization probe that is complementary to an HLA DNA sequence involved in the polymorphism; and comparing the resulting genomic blotting pattern with a standard This technique may be adapted to make paternity or transplant or transfusion compatibility determinations or to make disease association correlations to diagnose diseases or predict susceptibility to diseases. Locus specific cDNA hybridization probes, particularly probes for genes of Class II loci (D and OR loci), for use in the typing procedure are described.