Mouse Cot-1 DNA™ is mouse DNA that is predominantly 50 to 300 bp in size and enriched for repetitive DNA sequences such as the B1, B2, and L1 family members. Mouse Cot-1 DNA™ is commonly used to block non-specific hybridization in microarray screening. It can also be used to suppress hybridization of rodent repetitive DNA sequences when mapping rodent clones by in situ hybridization or Southern blotting and to identify mouse clones in screens of somatic-cell hybrid libraries derived from mouse-hamster hybrid cells (1-3). The amount supplied is sufficient for 5 to 10 Southerns 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 Mouse Cot-1 DNA™ 1:100 in 50 mM NaOH and using the conversion factor 0.033 μg/μl/A 260 . Other methods used to determine concentration may yield varying results.