Abstract A rapid and sensitive in situhybridization method, using total genomic DNA probes, can specifically detect and identify the lactic acid bacteria in wine. The total genomic DNA probes were labelled with digoxygenin (DIG) by random priming and hybridized with the genomic DNA of the bacteria to be identified. The hybrids were detected with fluorescent anti-DIG Fab-fragments or with enzyme-conjugated anti-DIG Fab-fragments. The cell wall of the Gram-positive lactic acid bacteria was made permeable with a lysozyme treatment to allow the accessibility of the probe to the target DNA and the penetration of anti-DIG antibodies which specifically bound to their antigens. The total genomic DNA probes exhibited the same specificity with dot-blot and in situhybridization. The in situhybridization technique made possible the control of the bacterial population in wine at different stages of vinification of storage, and the identification of lactic acid bacteria which can cause wine spoilage.