Technology
A technique that utilizes immunoprecipitation to find protein-DNA interactions in a biological sample. First, the sample is treated causing the formation of protein-chromatin crosslinks. Then, the sample is sheared to separate individual protein-DNA complexes. Finally, an antibody directed against a protein of interest is applied and the protein-DNA complexes are immunoprecipitated.
Diagnostic Methods
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
A physical mapping approach that uses fluorescent tags to detect hybridization of probes within metaphase chromosomes or less condensed somatic interphase chromatin. This technique can be used for identification of chromosomal abnormalities and for gene mapping.
Diagnostic Methods
Technology
Hematoxylin-and-eosin, or H&E, is a routine staining procedure of tissue sections. This staining method uses two separate dyes, one staining the nucleus and the other staining the cytoplasm and connective tissue. Hematoxylin is a dark purplish dye that stains the chromatin (nuclear material) within the nucleus. Eosin is an orangish-pink to red dye that stains the cytoplasmic material including connective tissue and collagen.
Diagnostic Methods
Technology
A chromatographic separation technique based on the ability of proteins to bind specific ligands reversibly.
Diagnostic Methods
Technology
A chromatographic technique in which the stationary phase is solid while the mobile phase is gaseous samples. The gaseous samples are separated based on their different adsorption ability to the solid phase.
Diagnostic Methods
Technology
An analytical technique wherein gas chromatography is coupled to mass spectrometry in order to separate, identify, and quantify substances in a sample.
Diagnostic Methods
Technology
Gel permeation or sieve chromatography that is performed on porous gels that separate solutes on the basis of size. Smaller solutes are included within the particles of the gel matrix more frequently than larger solutes, thus affecting elution rates.
Diagnostic Methods
Technology
Frequently referred to simply as HPLC, this form of column chromatography is used frequently in biochemistry. The analyte is forced through a column by liquid at high pressure, which decreases the time the separated components remain on the stationary phase. Less time on the column then translates to narrower peaks in the resulting chromatogram and thence to better selectivity and sensitivity.
Diagnostic Methods
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Affinity chromatography using monoclonal or polyclonal antibodies, or (less commonly) antigens, as the immobilized binding phase.
Diagnostic Methods
Technology
A type of chromatography assay in which an antibody-conjugate is passed over an immobilized antigen, giving a visual indication of positive or negative result.
Diagnostic Methods