“…Restriction endonuclease fragment analyses by molecular hybridisation with radioactively labelled, cloned gene probes are useful for monitoring gene polymorphisms in Saccharomyces strains (15,18,19,20,21,22,23). In a previous paper, top fermenting ale strains could be distinguished from bottom fermenting (lager) strains by polymorphisms at the HIS4 and the RDN1 loci (20), but only the Bavarian Pschorr Abbreviations: SSC = 0.15 M-NaC1, 15 mM-Na citrate; TBE = 90 mM-Tris base, 90 mM-boric acid, 2 mM-EDTA, pH 8.3; TE = 10 mM-Tris HC1, 1 mM-EDTA, pH 7.5. strain could be separated from other bottom fermenting strains.…”