COT Human DNA 11581074001

The COT fraction of human genomic DNA consists largely of rapidly annealing repetitive elements. These interspersed repetitive sequences (IRS) such as SINEs (small interspersed repetitive elements, e.g., Alu-elements) and LINEs (large interspersed repetitive elements, e.g., L1-elements) are distributed ubiquitously throughout the genome. COT Human DNA is prepared from human placental DNA by shearing, denaturing, and reannealing under conditions that enrich these repetitive elements.
Repetitive elements (IRS) present in a probe (e.g., cosmids, YACs, chromosome painting probes) generate nonspecific hybridization signals that are distributed over the whole chromosome or genome. To enable specific hybridization of the probe to the chromosomal target site (e.g., single-copy sequences or low-copy repeats) the probe must be denatured in the presence of excess unlabeled COT Human DNA. This DNA serves as a competitor. In a subsequent preannealing step, the repetitive probe elements rapidly hybridize to excess repeats in the COT Human DNA, while most of the specific probe sequences remain single-stranded and thus can be hybridized to their chromosomal targets. This technique is known as chromosomal in situ suppression (CISS) hybridization.
COT Human DNA is used in chromosome in situ suppression (CISS) hybridization. Cosmid or YAC probes contain repetitive elements that result in monospecific hybridization signals distributed over the entire chromosome. To enable specific hybridization to the chromosomal target site, the probe is denatured together with an excess of unlabeled COT Human DNA as a competitor. COT Human DNA can be used to suppress nonspecific hybridization to human repetitive sequences in microarray analysis, and in filter and in fluorescent in situ hybridization experiments.
Sequence
In agarose gel electrophoresis the length distribution of the COT Human DNA fragments shows a maximum in the range of 50 to 300 nucleotides.
Physical form
Solution, 1 mg/ml, 10 mM Tris-HCl, 1 mM EDTA, pH 7.4
For life science research only. Not for use in diagnostic procedures.

Quality Level	100,
form	solution
packaging	pkg of 500 µg
Торговая марка	Roche
shipped in	dry ice
storage temp.	20°C

RIDADR	NONH for all modes of transport
WGK Germany	nwg
Flash Point F	No data available
Flash Point C	No data available