Detrimental Effect of Formaldehyde on Plasma RNA Detection

Abstract

Recent studies have shown that detection of fetal DNA or RNA in maternal plasma is useful for prenatal investigation of certain fetal genetic traits (1)(2) or pregnancy-associated complications (3)(4). Fetal DNA has been shown to amount to 3.4%–6.2% of the total DNA in maternal plasma (5). Thus, the reliability of circulating fetal nucleic acids analysis is dependent on the ability to sensitively and specifically detect and distinguish such fetal molecules from a background of maternal nucleic acids. Hence, methods that enable enrichment of the proportion of fetal nucleic acids in maternal plasma would, in theory, facilitate robust analysis of circulating fetal nucleic acids. Dhallan et al. (6) recently explored the use of formaldehyde for the enrichment of circulating fetal DNA. The authors reported marked increases in the proportion of fetal DNA in maternal blood samples preserved with formaldehyde. Although controversies exist regarding the …