A reliable and reproducible non-radioactive DNA fingerprinting techniq
ue has been used to differentiate between twelve production brewery ye
ast strains. The method comprises total DNA preparation from the yeast
strains, enzymatic digestion of the DNA and analysis of the DNA fragm
ents by ''probing'' with known DNA labelled with the plant steroid dig
oxigenin. A range of probes and several enzymes have been investigated
. A successful combination is the restriction endonuclease Hind III an
d a probe derived from Ty1 (a yeast transposable element). The main ad
vantages of this method are its unambiguity, reproducibility and suita
bility for routine brewery QC use.