Dot Blots

Example of Dot Blot: a probe specific of the transgene is labeled (here radioactive) and used to hybridize a membrane spotted with DNA extracted from different mice. The intensity of the signal obtained is compared to control dots representing different number of copies of the transgene in the genome (bottom line: here 0 copy, 5, 10, 15 and 20). We can then approximate the number of copies of the transgene for a particular animal (here, for example animal 2046 contains between 5 and 10 copies)