N scanning / N-chip

1. Technical Aspects

 

Chance of having a baby with chromosomal abnormalities such as Down syndrome increases with maternal age. Chorionic villus sampling (CVS) and amniocentesis are typically performed to diagnose problems for mothers older than 35 or belonging to a high risk group after biochemical screening Cytogenetic examinations determine chromosomal abnormalities in metaphase by microscopy. However, CVS and amniocentesis are invasive tests with the risk of miscarriage.

 

N scanning is a new screening method suggested by MGMED, an advanced screening technique to obtain fetus’s chromosomal abnormalities information from cell free DNA in maternal blood. This is a non-invasive screening technique using cell-free fetal DNA in maternal blood.

2. Procedure

 

N-chip is a DNA chip designed for a high-resolution approach to detect chromosomal abnormalities in fetus. DNA fragments which represent the major regions of fetal genome are attached to the chip. In a clinic, fetal cells are collected from maternal bloods. DNA is extracted from the fetal cells, labeled with green fluorescent dye, and hybridized. Normal DNA labelled with red fluorescent dye is competitively hybridized as a control. By comparing relative fluorescence signal, numerical and structural chromosomal abnormalities are detected