A Micromachined Sparse-Cell Isolation Device: Application in Prenatal Diagnostics

Fetal cells can be isolated using several enrichment methods, however, since no technique to specifically isolate and use them for genetic diagnosis has reached clinical practice, prenatal diagnosis currently requires invasive procedures. A micromachined device to fractionate whole blood using physical means to enrich for and/or isolate rare cell types from peripheral circulation was designed. It has arrays of four successively narrower channels, each consisting of a 2-D array of columns. Current devices have channels ranging in width from 15μm-2.5μm, and are 5μm deep. Fetal nucleated red blood cells were isolated from cord blood reproducibly and molecular analysis confirmed their origin without contamination from maternal DNA. Future studies will provide methods to detect fetal cells from maternal circulation using a non-invasive approach, the risk for fetal loss will be eliminated, and test costs will be decreased.