Direct in-gel hybridization of digoxigenin-labelled nonradioactive probes

An improved, simple, cost-effective and non-radioactive procedure for in-gel hybridization is described for the detection of signal in dried agarose gels. Large and smalt digoxigenin-labelled DNA and oligonucleotide probes hybridized efficiently and specifically with the complementary DNA sequences in the gel. The signal-to-noise ratios for the gels dried at 55 degrees C at 1 atmospheric pressure were 3-3.5-fold higher than the gels dried at 25 degrees C under vacuum. The method shows an increased sensitivity over currently available non-radioactive methods for in-gel hybridization. A single copy of a gene insert could be detected by the use of this procedure. (C) 1999 Academic Press.