# The labeled samples are then mixed with a propriety hybridization solution which may contain SDS, SSC, dextran sulfate, a blocking agent (such as COT1 DNA, salmon sperm DNA, calf thymus DNA, PolyA or PolyT), Denhardt's solution and formamine.
The second method involves the Radziszewski reaction from glyoxal, formaldehyde, and a mixture of ammonia and methylamine.