Human Cot-1 DNA™ is commonly used to block nonspecific hybridization in microarray screening. It can also be used to suppress repetitive DNA sequences for the direct mapping of human DNA or mapping genomic clones to panels of somatic-cell hybrids for chromosome localization by Southern blotting. Human Cot-1 DNA™ is effective as a library-screening probe for somatic-cell hybrid libraries and flow-sorted chromosome libraries made from somatic-cell hybrids.

About Cot-1 DNA™
Human Cot-1 DNA™ is placental DNA that is predominantly 50 to 300 bp in size and enriched for repetitive DNA sequences such as the Alu and Kpn family members. The amount supplied per package is sufficient for 5–10 Southern or 500 in situ hybridizations.

Performance and quality testing
Purity and DNA size are verified by agarose gel electrophoresis. Concentration is verified spectrophotometrically by diluting Human Cot-1 DNA™ 1:100 in 50 mM NaOH and using the conversion factor 0.033 μg/μL/A₂₆₀. Other methods used to determine concentration may yield varying results.