Chapter 2. Morphological and Biochemical Heterogeneity of Amniotic Fluid Cells in Culture

Abstract

This chapter describes the morphological and biochemical heterogeneity of amniotic fluid cells in culture. Midgestation amniotic fluid cells constitute a precious source of human cells for the purpose of cell biological investigation. Several properties contribute to the diagnostic and scientific value of these cells, the most important of which are the presence in a single amniotic fluid specimen of multiple, morphologically and biochemically distinct cell types that are all derived from the fetus or from fetal membranes and thus are isogenic. It is found that in addition to variable amounts of cellular debris and anucleate particles, second-trimester amniotic fluid contains between 103 and 105 nucleated cells per milliliter of fluid. All epithelial surfaces in direct or indirect contact with the amniotic cavity are possible sites of origin of these cells. According to their behavior in the culture environment, nucleated amniotic fluid cells can be operationally divided into three separate categories. The first category includes cells that remain afloat even after prolonged periods of incubation. It is found that amniotic fluid F-type cells have the greatest in vitro growth potential of all colony-forming cells.