Optimization of nucleated red blood cell (NRBC) recovery from maternal blood collected using both layers of a double density gradient

Non-invasive prenatal diagnosis of aneuploidies: new technologies and clinical applications

“…The first step involves Ficoll-Paque or Percoll-gradient density centrifugation to remove mature red blood cells and granulocytes, leaving peripheral mononuclear cells [34,38]. Further enrichment is usually achieved using methods such as fluorescence-activated cell sorting (FACS) [31,39], magnetic-activated cell sorting (MACS) [40,41] or charge flow separation [42].…”

The use of non-physiological conditions to isolate fetal cells from maternal blood

“…Simple and/or double density gradients have been described, to isolate fetal cells from maternal blood using either Percoll or Ficoll-solutions of different densities, reviewed by Prieto et al [26] and Samura et al [27]. Different results were obtained although a general agree- ment was reached that NRBCs are distributed both in the light and in the heavy portion of the gradient and that no difference exists in the density distribution profile of fetal and adult NRBCs.…”

Situación actual del diagnóstico prenatal no invasivo

“…Proporciona un buen rendimiento pero una pureza baja, ya que se aísla un elevado número de células mononucleadas de la serie blanca. Además, la distribución de los eritroblastos en el gradiente de densidad está afectada por el tiempo transcurrido entre la recogida de la muestra y su procesamiento 31 . Otra opción es la lisis selectiva de las células de la serie roja con cloruro de amonio 32 .…”

“…Hasta el momento no se han descubierto antígenos de superficie específicos de eritroblastos fetales, por lo que el uso de anticuerpos anti-CD71 (comerciales 40 o no comerciales 31,41,42 ) ha sido la alternativa más frecuente.…”