Detection of specific RNA sequences in yeast by in situ colony hybridization

Recently a convenient method for detection of specific RNA sequences in bacteria has been developed but the original protocol was inapplicable to microorganisms with a rigid cell wall. Here we report a modification of the RNA colony hybridization for use with yeast. The modified method includes the following consecutive procedures: a) treatment of the yeast colonies on the membrane filter with 10% SDS at 65% C for 30 min; b) treatment of the same filter with 3 x SSC, 10% formaldehyde at 65 degrees C for 30 min; c) hybridization with 32P-labelled oligonucleotide (or DNA) specific for the RNA sequence of interest. The intensity of the radioactive signals thus obtained is comparable with that of the E. coli colonies.