Applied Biosystems

About: Applied Biosystems is a based out in . It is known for research contribution in the topics: Mass spectrometry & Nucleic acid. The organization has 1521 authors who have published 1579 publications receiving 285423 citations.

Method of synthesizing oligonucleotides labeled with ammonia-labile groups on solid phase supports

Abstract: The invention provides a novel cleavage reagent for hydrolysing base-labile linking groups between a solid phase support and oligonucleotides. The cleavage reagent comprises a lower alkyl alcohol, water, and a non-nuccleophilic hindered alkylamine containing from 3 to 6 carbon atoms in a ratio of about 1:1:1 to about 1:3:1, respectively. An important property of the cleavage reagent is that it preserves the fluorescent characteristics of rhodamine dyes during cleavage, thereby making it possible to completely synthesize rhodamine-labeled oligonucleotides by solid phase methods. Rhodamine phosphoramidites are provided to further enhance the efficiency of synthesizing rhodamine-labeled oligonucleotides by such methods.

Time-of-flight mass spectrometer with an aperture enabling tradeoff of transmission efficiency and resolution

Abstract: not available for EP0587707Abstract of corresponding document: US5300774A time-of-flight mass spectrometer in which sample ions are generated from a target and are focussed into an ion beam that is incident onto a detector. A barrier that defines an aperture in the path of the ion beam is positioned to block ions having an extra large deviation from an average time-of-flight of the ions, thereby improving resolution. The aperture can be adjusted to adjust a tradeoff between sensitivity and resolution. Alternatively, the position of the aperture or the bias on an einzel lens can be adjusted to control this resolution.

HLA haplotypes and susceptibility to rheumatoid arthritis. More than class II genes.

Abstract: Our aim was to examine, using microsatellite (ms) markers, the contribution of the telomeric part of the HLA region to rheumatoid arthritis (RA) predisposition in the Spanish population. We have looked at the distribution of DQB1, DRB1 and five ms loci ( D6S1014, D6S273, D6STNFa, MIB and C1-2-5 ) within the HLA region in 147 Spanish RA patients and 202 control subjects. A total of 19 conserved ms configurations were observed, twelve of them in linkage disequilibrium with particular DQB1-DRB1 haplotypes. Interestingly, haplotype c1 ( DQB1*0201-DRB1*0301-D6S1014*143-D6S273*139-D6STNFa*99-MIB*350-C1-2-5*196 ) was significantly associated with RA predisposition. As part of this haplotype, the MIB *350 allele was found to be a risk factor independently of the RA-predisposing haplotypes. The present results along with data from others prove the existence of a second predisposing locus located inside the MHC region, and suggest that might be located within the TNFa-HLA-B region.