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.

Patterns of linkage disequilibrium in the MHC region on human chromosome 6p.

Abstract: Single nucleotide polymorphisms (SNPs) in the human genome are thought to be organised into blocks of high internal linkage disequilibrium (LD), separated by intermittent recombination hotspots. Since understanding haplotype structure is critical for an accurate assessment of inter-individual genetic differences, we investigated up to 968 SNPs from a 10-Mb region on chromosome 6p21, including the human major histocompatibility complex (MHC), in five different population samples (45-550 individuals). Regions of well-defined block structure were found to coexist alongside large areas lacking any clear structure; occasional long-range LD was observed in all five samples. The four white populations analysed were remarkably similar in terms of the extend and spatial distribution of local LD. In US African Americans, the distribution of LD was similar to that in the white populations but the observed haplotype diversity was higher. The existence of large regions without any clear block structure renders the systematic and thorough construction of SNP haplotype maps a crucial prerequisite for disease-association studies.

Methods and systems for using RFID in biological field

Abstract: Biological reagent carrier devices and methods are disclosed, which employ RFID techniques to associate information with biological reagents.

Improved quantitative PCR using nested primers.

Abstract: Quantitative PCR can often be improved by conducting the amplification with nested primers. First, fewer nonspecific amplification products, which could otherwise interfere with quantitation, are produced. Often, nonspecific products can be eliminated. In these cases, relatively simple nonspecific detection techniques are suitable for quantitation. In addition, nested primer PCR provides intrinsic PCR product carryover protection and generally improves the robustness and lower limit of detection of PCR. For a nested PCR to provide useful quantitative information, it is important that the initial phase of amplification, performed with the outer pair of primers, takes place entirely in the exponential phase. This is generally achieved easily. The major consideration in designing a nested PCR protocol compatible with quantitation is to assure that the maximum concentration of PCR products produced by the outer primers does not exceed approximately 10% the molarity of the outer primers. A simple formula can be used to determine the maximum number of thermal cycles that provide this assurance. Good correspondence was obtained between initial target concentration and final PCR product yield in a nested-primer HIV-1 PCR.

Evaluation of external RNA controls for the assessment of microarray performance

Abstract: External RNA controls (ERCs), although important for microarray assay performance assessment, have yet to be fully implemented in the research community. As part of the MicroArray Quality Control (MAQC) study, two types of ERCs were implemented and evaluated; one was added to the total RNA in the samples before amplification and labeling; the other was added to the copyRNAs (cRNAs) before hybridization. ERC concentration-response curves were used across multiple commercial microarray platforms to identify problematic assays and potential sources of variation in the analytical process. In addition, the behavior of different ERC types was investigated, resulting in several important observations, such as the sample-dependent attributes of performance and the potential of using these control RNAs in a combinatorial fashion. This multiplatform investigation of the behavior and utility of ERCs provides a basis for articulating specific recommendations for their future use in evaluating assay performance across multiple platforms.