Quite often the gel electrophoretic migration pattern of individual components in a sample is determined not by analysing the gel but rather by analysing an image of the gel created by blotting the gel on to membrane. One of the simplest procedures is capillary blotting. However, for blotting DNA gels using Zeta-Probe, the blotting can be done in alkali, in which case the denatured DNA becomes fixed to the filter.