EDTA-mediated inhibition of DNases protects circulating cell-free DNA from ex vivo degradation in blood samples.

Objetives: The extracellular DNA occurring in plasma-EDTA and serum is a biomarker of growing interest, especially in prenatal diagnosis and oncology. The objectives of the present study were to compare the DNase activity in these specimens and to investigate its ex-vivo impact over the circulating cell-free DNA yield (ccfDNA), using the circulating cell-free fetal DNA (ccffDNA) as a tool.

Design And Methods: EDTA-plasma and serum from women bearing male fetus were submitted to an endogenous DNase activity assay based on qPCR hydrolysis probe degradation, they were treated with DNAse I to investigate the action of an exogenous nuclease and also submitted to different temperature conditions to investigate the temperature-dependent degradation of the ccffDNA.

Fetal male lineage determination by analysis of Y-chromosome STR haplotype in maternal plasma.

The aim of this study is to determine the fetus Y-STR haplotype in maternal plasma during pregnancy and estimate, non-invasively, if the alleged father and fetus belong to the same male lineage. The study enrolled couples with singleton pregnancies and known paternity. All participants signed informed consent and the local ethics committee approved the study.

Haplotype diversity of 23 Y-chromosomal STRs in a population sample from the Federal District (Brazil)--a territory that arose from nothing.

In this study, the genetic variations of 23 short tandem repeats on the Y-chromosome were analyzed in a sample of 201 males from the Federal District (Brazil). The Federal District (Brazil) was built in 1960 in Brazil's Central West region, where there was no previous population. In 2010, the population of this artificially founded district consisted of 2,500,000 inhabitants.

Allele frequencies for 15 autosomal STRs in a population sample from the Federal District (Brazil)-a territory that arose from nothing.

The Federal District (Brazil) was created in 1960 in the Central-West Region of Brazil in a previously unpopulated area. In 2010, this artificially founded district was populated by 2,562,963 inhabitants. In this study, the genetic variations of the 15 Next Generation Multiplex (NGM(TM)) short tandem repeat loci were analyzed.