Technology
A molecular genetic technique that isolates and sequences chromosomal regions that are rich in open chromatin. First, nuclei are harvested from a cellular sample. Then a hyperactive Tn5 transposase is added to the nuclei where it excises non-nucleosomal DNA strands and ligates co-administered high-throughput sequencing adapters (tagmentation). The tagged DNA fragments are isolated, amplified by PCR and sequenced. The number of reads for specific region of DNA correlate with increased chromatin accessibility and this method can identify regions of transcription factor and nucleosome binding.
Diagnostic Methods
Technology
A molecular genetic technique that combines chromatin immunoprecipitation (ChIP) with massively parallel DNA sequencing to map the binding sites of DNA-associated proteins in a sample of cells. First, crosslinked protein-DNA complexes are isolated using ChIP. Next, the crosslinks are broken, the proteins are removed and the purified DNA is modified with adaptor oligonucleotides to facilitate massively parallel DNA sequencing. Following sequencing, the DNA sequences that are obtained can be mapped to their genomic locations.
Diagnostic Methods
Technology
The treatment of chromosomes to reveal characteristic patterns of horizontal bands. The banding patterns lend each chromosome a distinctive appearance so the 22 pairs of human non-sex chromosomes and the X and Y chromosomes can be identified and distinguished without ambiguity. Banding also permits the recognition of chromosome deletions (lost segments), chromosome duplications (surplus segments) and other types of structural rearrangements of chromosomes.
Diagnostic Methods
Technology
A molecular biology technique used to detect the interaction of a DNA binding protein with its cognate binding sequence. Labeled DNAs were reacted with crude cell extracts and the complexes are run through a non-denaturing polyacrylamide gel. The migration of the labeled DNA through the gel will be slower by being bound. This shift in electrophoretic mobility indicates functional binding between the protein and the DNA.
Diagnostic Methods
Technology
A type of homogenous immunoassay in which sample is applied to a reagent mixture of enzyme-labeled ligand, antibody, and substrate. Substrate binding to enzyme leads to inactivation and unlabeled-ligand in the sample can be quantified by colorimetric analysis.
Diagnostic Methods
Technology
Use of Giemsa stain to produce a characteristic staining pattern on chromosomes
Diagnostic Methods
Technology
Affinity chromatography using monoclonal or polyclonal antibodies, or (less commonly) antigens, as the immobilized binding phase.
Diagnostic Methods
Technology
A type of enzyme immunoassay that uses antigen-coated microparticles as a substrate for antibody binding.
Diagnostic Methods
Technology
Analytical and separative procedures in which molecules, particularly proteins or nucleic acids, are separated by their different electrophoretic mobilities in a hydrated gel. The gel suppresses convective mixing of the fluid phase through which the electrophoresis takes place and contributes molecular sieving. For proteins, commonly carried out in the presence of the anionic detergent sodium dodecylsulphate (SDS). SDS denatures proteins so that noncovalently associating sub unit polypeptides migrate independently and by binding to the proteins confers a net negative charge roughly proportional to the chain weight.
Diagnostic Methods
Technology
A quantum optical-electrical phenomena consisting of an alteration in light reflectance as a result of binding of molecules to a surface from which total internal reflection is occurring. Used to detect macromolecular interactions, SPR can be used as the basis for a sensor which is capable of sensitive and quantitative measurement of a broad spectrum of chemical and biological entities.
Diagnostic Methods