Methodological Standardization for the Extraction of Free DNA in Plasma of Peripheral Blood
Ary Serpa Neto1, Marcelo Langer Wroclavski1, Jorge Luiz Freire Pinto2, Sarah Rodrigues Marsicano2, Pamela Oliveira Delgado2, Patricia Granja Coelho2, Ricardo Moreno2, Viviane Aparecida Vilas Boas2, Ligia Ajaime Azzalis3, Virginia Berlanga Campos Junqueira3, Auro Del Giglio1 and Fernando Luiz Affonso Fonseca2,3*
- *Corresponding Author:
- Ary Serpa Neto, MD
Department of Clinical Oncology and Hematology
ABC Foundation School of Medicine
Av. Lauro Gomes, 2000, São Paulo, Brazil
E-mail: [email protected]
Received Date: November 27, 2011; Accepted Date: February 02, 2012; Published Date: February 06, 2012
Citation: Neto AS, Wroclavski ML, Freire Pinto JL, Marsicano SR, Delgado PO, et al. (2012) Methodological Standardization for the Extraction of Free DNA in Plasma of Peripheral Blood. J Cancer Sci Ther S5:005. doi:10.4172/1948-5956.S5-005
Copyright: © 2012 Neto AS, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Background: Biological materials such as cells, DNA, RNA, and proteins can be recovered from blood, urine, feces, pancreatic juice and sputum of patients. Here, we described a method for free plasma DNA extraction used in our laboratory, compared it to one of the most reproduced in the literature, and also verified the effects of short time storage of plasma on DNA quantification.
Methods: We assessed DNA concentrations in four samples of peripheral blood one hour, one day and three days after plasma separation (part A). EDTA blood (10 mL) was collected from each individual (10) and the specimen was centrifuged at 1,300 g for 10 min. The supernatant was transferred into polypropylene tubes, with particular attention not to disturb the buffy coat layer and the plasma was microcentrifuged at 2,400 g. DNA extracted from plasma was quantified (part B).
Results: Mean DNA concentration after our extraction process was similar to those methods found in literature. Moreover, we found a consistently negative correlation between time after plasma collection and DNA concentrations (r = -0.568; p = 0.022).
Conclusion: We showed a new method for DNA extraction. Also, we verified that fast processing after plasma collection was necessary to produce realistic results of plasma DNA.