A sensitive and dependable assay for distinguishing hamster and human X-linked steroid sulfatase activity in somatic cell hybrids

Abstract
A radioisotopic assay is described to distinguish between Chinese hamster and human steroid sulfatase activity in extracts prepared from hamsterxhuman somatic cell hybrids. This assay is based on different pH optima and provides a sensitive and unambiguous biochemical marker for the short arm of the human X chromosome and as well as for otherwise genetically inactivated X chromosomes in rodentxhuman hybrids.