A HAMMERHEAD RIBOZYME CLEAVES ITS TARGET RNA DURING RNA PREPARATION

A chemically modified hammerhead ribozyme was designed to cleave the t ax RNA of human T cell leukemia virus type I. This ribozyme was exogen ously delivered to tax-transformed fibroblasts by DOTAP-mediated trans fection. The analysis of RNA from ribozyme-transfected cells by RNase protection detected ribozyme cleavage products. However, control exper iments revealed that the ribozyme did not cleave its target RNA intrac ellularly but during the course of the RNA isolation. This suggests th at great care should be exercised when interpreting in vivo results of ribozyme cleavage.