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.

Labeling by simultaneous ligation and restriction

Abstract: Termini of restricted double-stranded DNA fragments are modified by ligating the fragments with terminal phosphate-free double-stranded oligonucleotides having a complementary terminus in the presence of a restriction enzyme and a ligase, where joining of the complementary ends results in loss of the restriction enzyme recognition sequence.

Testing genotypic and phenotypic resistance in human immunodeficiency virus type 1 isolates of clade B and other clades from children failing antiretroviral therapy.

Abstract: The emergence of resistance to antiretroviral drugs is a major obstacle to the successful treatment of human immunodeficiency virus type 1 (HIV-1)-infected patients. In this work, we correlate clinical and virological trends such as viral load (VL) and CD4 counts to genotypic and phenotypic antiretroviral (ARV) resistance profiles of HIV-1 isolates from the B and non-B subtypes found in vertically infected children failing ARV therapy. Plasma samples were collected from 52 vertically HIV-1-infected children failing different ARV therapies. Samples underwent HIV-1 pol sequencing and phenotyping and were clustered into subtypes by phylogenetic analysis. Clinical data from each patient were analyzed together with the resistance (genotypic and phenotypic) data obtained. Thirty-five samples were from subtype B, 10 samples were non-B (subtypes A, C, and F), and 7 were mosaic samples. There was no significant difference concerning treatment data between B and non-B clades. Prevalence of known drug resistance mutations revealed slightly significant differences among B and non-B subtypes: L10I, 21 and 64%, K20R, 13 and 43%, M36I, 34 and 100%, L63P, 76 and 36%, A71V/T, 24 and 0%, and V77I, 32 and 0%, respectively, in the protease (0.0001 ≤ P ≤ 0.0886), and D67N, 38 and 8%, K70R, 33 and 0%, R211K, 49 and 85%, and K219Q/E, 31 and 0%, respectively, in the reverse transcriptase (0.0256 ≤ P ≤ 0.0704). Significant differences were found only in secondary resistance mutations and did not reflect significant phenotypic variation between clade B and non-B.

Liquid processing device including gas trap, and system and method

Abstract: A device is provided that can include at least one gas trap that can be arranged in fluid communication with a sample-containment feature formed in or on the device. The gas trap can be arranged to trap gas or air displaced from the sample-containment feature as the sample-containment feature is loaded with a liquid. The trapped gas in the gas trap can assist in breaking-up and expelling the liquid from the sample-containment feature during a subsequent liquid transfer operation, for example, to an adjacent sample-containment feature. Systems for processing such a device and methods using such a device are also provided.

Enzymatically-cleavable chemiluminescent fused polycyclic ring-containing 1,2-dioxetanes

Abstract: Chemiluminescent 1,2-dioxetane compounds are disclosed in which the molecule is stabilized at the 3-position on the dioxetane ring against decomposition prior to the molecule's coming in contact with a labile group-removing substance (e.g., an enzyme that will cleave the labile group to cause the molecule to decompose to form at least one light-emitting fluorophore) and substituted at the 4-position on the dioxetane ring with a fused polycyclic ring-containing fluorophore moiety bearing a labile ring substituent whose point of attachment to the fused polycyclic ring, in relation to this ring's point(s) of attachment to the dioxetane ring, is such that the total number of ring atoms separating these points of attachment, including the ring atoms at the points of attachment, is an odd whole number. These odd pattern substituted compounds decompose to emit light of greater intensity and of a different wavelength than that emitted by the corresponding even pattern substituted isomers. They are useful in detecting the presence or determining the concentration of chemical or biological substances in immunoassays, chemical assays and nucleic acid probe assays, and in chemical/physical probe procedures for studying the microstructures of macromolecules. Two or more of them can also be used in combination, or one or more of them can be used together with other chemiluminescent compounds, in multi-channel assays to detect two or more different analytes simultaneously. Novel intermediates used in the preparation of these odd pattern substituted compounds are also disclosed.