Template activity of unfixed metaphase chromosomes.

Unfixed metaphase and non-metaphase cells were tested for their template activity with RNA polymerase. A device was used which disrupts the cell membrane by centrifugation, and which also ensures that the cells do not continue with their mitotic cycle during the transcription process. The template activity of acid/methanol fixed cells was also tested. None of the unfixed metaphase cells transcribed RNA whereas most of the non-metaphase cells did. In contrast, using fixed cells both classes of cells were transcribed equally well and to a much greater extent. It was concluded that metaphase chromosomes in vivo cannot act as templates for RNA synthesis.