Electron microscopic demonstration of transcription of ram sperm chromatin

Transcription of ram sperm chromatin was examined by two electron microscopic techniques, namely spreading and thin sections. Labelling by Streptavidin-gold particles permits identification of transcription complexes, that have previously incorporated biotinylated uridine triphosphate. This supports previous electron microscopic data for randomly distributed transcription complexes and the presence of polymerase II molecules, documented by means of specific antibody using immunoelectron microscopy. Labelling of transcripts with biotin permits exact visualization of the transcription process, as well as identification of regions, where transcription occurs.