[Detection of mRNA by in situ hybridization in tissues fixed in Bouin's fixative and embedded in paraffin]

Human skeletal tissues fixed in Bouin's solution and embedded in paraffin were studied in order to identify cells responsible for production of types I and II collagens by in situ hybridization. The probes used were a double stranded cDNA fragment (type I collagen) and a synthetic oligonucleotide (type II collagen). The specificity of these probes labeled with 32P was proven in hybridizations to sections of human fetal femoral heads: fibroblasts and chondrocytes, known to produce respectively type I and type II collagen were only recognized by the corresponding probes. These results suggest that paraffin blocks available in pathology departments could be reexamined by in situ hybridization. Furthermore, the use of synthetic oligonucleotides without cloning the gene of interest could increase the usefulness of the technique in studies on human cartilage diseases and possibly on other diseases.