Capillary Blotting of Agarose Gels

Southern blotting is a well-known technique (1 ). DNA is cleaved with restriction enzymes (Chapter 2 ) to produce fragments that are fractionated according to their size in an agarose gel (Chapter 3 ). The DNA is then partially cleaved by depurination (to facilitate the transfer of larger DNA fragments) and alkali denatured by sequential soaking of the gel in solutions containing HCl and NaOH, respectively. The denatured DNA fragments are then transferred to a solid matrix or filter (usually a nylon membrane) for subsequent hybridization to a specific labeled probe (Chapter 6 ).