Isolation and characterization of syncytiotrophoblast plasma membrane from human placenta.

Human full-term syncytiotrophoblast plasma membranes isolated by mechanical procedures (sieving and ultrasonic disintegration), purified by phase centrifugation, form a single band of 1.052 +/- 0.002 g/ml density in percoll gradient. The purity of the preparation was assessed by electron microscopy, enzyme analysis and beta 2-microglobulin determination.