• Investigating the effect of utilizing Lysis Buffer in the DNA extraction protocol of frozen blood
  • Fatemeh Afkhami,1,* Hamid Galehdari,2
    1. MSc in Genetics, Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
    2. Department of Biology, Faculty of Sciences, Shahid Chamran University of Ahvaz, Ahvaz, Iran.


  • Introduction: Progress in any scientific field depends on the availability of new and advanced techniques and methods which are considered important for medical diagnosis tests in diseases that have a genetic origin and also for extracting DNA from blood and tissues. One of the problems that sometimes occurs with genomes in tropical regions is the freezing and unfreezing of old genomes, which can occur for various reasons: including power outages, hot weather and etc. This issue causes excessive fragmentation of the genome, which may lead to false results or no results in the research process; Therefore, in this article, an attempt has been made to investigate a better method for extracting the genome from frozen blood.
  • Methods: In this study, to achieve a better result, a total of 450 blood samples of the human genome that were frozen and refrozen at least four times were used. At first, these samples were extracted using the salting method and only water was used for washing. Again, they were extracted from blood cells using a lysis buffer with NH4Cl, NaHCO3 and EDTA compounds.
  • Results: Due to the use of lysis buffer instead of water, the washing rate of old genomes and centrifugation cycle (8500rpm) to separate nucleated cells was reduced and white Cells were observed earlier in the sediment. The need for vortex in different stages was also reduced and the amount of use of solutions of TES, SDS and proteinase k(Cinnagen) were also reduced, which were 300,25,20 µL respectively. Finally, The quality and quantity of extracted genomes were checked (figures 1, 2) Figure-1:Agarose gel electrophoresis (1%) with DNA extracted from blood samples Figure 2: Absorption diagram through nanodrop device
  • Conclusion: The physical as well as chemical treatments involved in DNA extraction can affect both the quantity and quality of the DNA obtained. In this regard, the present study showed that extracting DNA from old and broken blood samples requires great accuracy. For example, using the right detergent to reduce the amount of washing, vortexing and centrifugation can reduce the amount of genome breakage and be effective in the quality and quantity of the extracted genomes.
  • Keywords: DNA extraction ;salting-out protocol; Genome; lysis Buffer