Enhancement of human amniotic cell growth by Ficoll-Paque gradient fractionation.

Ficoll-Paque isopycnic centrifugation was used as a preparative procedure for amniotic fluid (AF) cells prior to tissue culture. This technique serves to reduce contaminating erythrocytes and also enhances cell growth or mitotic indices. The technique described in this report yields three subfractions designated as a turbid interphase layer (F-2), a middle cell layer (F-3), and a bottom pellet (F-4). The middle cell layer (F-3) demonstrated better cell growth and higher mitotic index than any of the other fractions or control unfractionated amniotic fluid cells. The use of Ficoll-Paque isopycnic preparative centrifugation of amniotic fluid cells is a valuable adjunct in cell culture for cytogenetic analysis. This may be especially true when amniotic fluid contains large numbers of erythrocytes.