The random primer labeling technique applied to in situ hybridization on tissue sections.

We report an application of the random primer labeling technique to in situ hybridizations on tissue sections. The ease of the method and the high specific activity achieved make it valuable when a large number of probes must be analyzed and high sensitivity is needed. We have applied this technique to study the spatial expression of a cluster of maternally acting genes (the yema gene region of Drosophila melanogaster which encodes eleven transcripts, some of them having a very low level of expression) (Aït-Ahmed et al., 1978: Dev Biol 122:153; Aït-Ahmed et al., unpublished results). The results reported here concern one of the transcripts of the yema region, which displays a peculiar anterior localization in the oocyte. We demonstrate that the "oligo-labeling" method allows a far better level of detection of the transcript of interest.