Evaluation of two DNA extraction methods from maternal plasma for using in non-invasive bovine fetus gender determination

Background: fetal dna in maternal plasma and serum has been shown to be a useful material for prenatal fetal sex determination during early gestational ages. non-invasive prenatal diagnosis is now possible at 8th week of pregnancy,by maternal blood sample testing. objective: the purpose of this study was to evaluate two dna extraction methods from mother plasma and its routine clinical application in bovine fetus gender determination with non-invasive method. materials and methods: maternal blood samples were taken from 40 pregnant cows during the 8th-38th weeks of gestation. dna was extracted from 350 μl of maternal plasma with two salting-out and phenol-chloroform methods. the absorption in a260 and purity (a260/a280) of extracted dna were detected by ultraviolet spectrophotometer. three μl of the extracted dna with phenol-chloroform method was used as a template. the pcr reaction was carried out to amplify the fragments of x and y chromosomes of amelogenin,tspy and bc1.2 genes. results: the difference between the mean absorption of dna extracted by phenol-chloroform method and salting-out method was not significant in a260 (p>0.05,p=0.3549),but the difference between mean purity (a260/a280) of dna extracted by phenol-chloroform method and salting-out method was significant (p<0.001). x chromosome fragment was detected in all 40 samples and y chromosome fragments were detected in 25 plasma samples which were delivered a male calf. the sensitivity and specificity of test was 100% with no false negative and false positive results. conclusion: the results showed that phenol-chloroform method is a simple and sensitive method for isolation of fetal dna in maternal plasma.