Secondary association of exogenous polynucleotides with cells and nuclei in uptake experiments

Manipulation of ³H]polynucleotide-treated cells to remove them from the substrate or to isolate nuclei has been shown to result in secondary association of the exogenous polynucleotide with the cells or nuclei. Experiments have shown untreated (control) cultures, when processed with supernatants from ³H]polynucleotide-treated cell monolayers, exhibited a significant amount of radioactive label associated with the nuclei from control cells. In spite of thorough washing of polynucleotide-treated cell monolayers prior to the manipulation, the association was extensive. It is likely to overshadow the association resulting solely from the exposure of monolayer cells to the polynucleotide.