THE NUCLEAR-MEMBRANE INTEGRITY ASSAY

A novel technique is described for the evaluation of membrane integrit y in isolated nuclei. Membrane integrity is assessed by measuring nucl ear fragility in response to high salt conditions. Salt-induced disrup tion of the nuclear membrane is followed by spectrophotometric monitor ing of released nucleotides. The assay is based on determining the amo unt of salt necessary to induce release of 50% of the total pool of re leasable nucleotides. This allows semiquantitative comparison of relat ive nuclear membrane strength or integrity of different samples in res ponse to high salt conditions. In this manner, the effects of altered nuclear membrane composition or metabolism on membrane integrity may b e monitored.