Evidence of inconsistency among laboratory technicians collecting dry blood spots for molecular analysis of Plasmodium falciparum dhfr gene

Abstract

In many biomedical researches, laboratory technicians who are not privy to the research design are recruited for sample collection. Their expertise can impact the output of very sensitive projects. This research aimed to determine whether laboratory technicians adhered to protocol for collection and preservation of filter paper dry blood spots for molecular analysis of P. falciparum dhfr gene. Four teams of laboratory technicians in Makurdi, Nigeria each, collected and preserved 20 positive P. falciparum dry blood spots on 3MM Whatman filter paper during supervision, and without supervision. The dhfr gene from the DNA of 80 randomly selected samples was amplified by nested polymerase chain reaction, to check the quality of DNA bands produced on gel electrophoresis by each mode of sample collection. The results showed that the supervised samples yielded 87.50% (35/40) of visible DNA bands, and 12.50% (5/40) of no visible DNA bands. The difference was significant (Binomial test p< 0.001). The unsupervised samples yielded 37.50% (15/40) of visible bands, and 62.50% (25/40) of no visible bands (Binomial test p= 0.15). The overall difference between supervised and unsupervised samples was significant (x²= 21.33, df= 1, p< 0.001). These results reveal that without some form of supervision, some laboratory technicians may ignore details, in sample collection protocols that can significantly lower the quality of the research output. Therefore, field supervision of sample collection for scientific research is encouraged to increase the quality of research output, reduce the waste of useful laboratory reagents, and hence the total project cost.

Keywords: Dry blood spots; P. falciparum; DNA; polymerase chain reaction.