Читать книгу Genetic Disorders and the Fetus - Группа авторов - Страница 125

Since cloning efficiency is low, it would be advantageous to increase the number of viable cells introduced into the cell cultures. Two studies have examined whether maternal activity or uterine agitation before amniocentesis affect the concentration of viable amniocytes in the fluid.^{636, 637} After correcting for gestational age, both studies were negative. Enrichment of the cell culture innoculum has been attempted via centrifugation of fluids through isopycnic gradients.⁶³⁸ With bloody specimens, these methods might be of some help but they are impractical for routine use. This limitation also holds for an enrichment technique by which the AF is returned to the fetus after aspiration, filtration, and reinjection of AF as early as 12.5 gestational weeks.^639–642