Review Article DNA, RNA, and Protein Extraction: The Past and The Present
Siun Chee Tan1 and Beow Chin Yiap2
of Postgraduate Studies & Research, Division of Pharmacy, International Medical University, No. 126, Jalan 19/155B, Bukit Jalil, 57000Kuala Lumpur, Malaysia 2 School of Pharmacy and Health Science, Division of Pharmacy, International Medical University, No. 126, Jalan 19/155B, Bukit Jalil, 57000 Kuala Lumpur, Malaysia Correspondence should be addressed to Siun Chee Tan, siunchee email@example.com Received 1 July 2009; Accepted 5 November 2009 Recommended by Joakim Lundeberg Extraction of DNA, RNA, and protein is the basic methodused in molecular biology. These biomolecules can be isolated from any biological material for subsequent downstream processes, analytical, or preparative purposes. In the past, the process of extraction and puriﬁcation of nucleic acids used to be complicated, time-consuming, labor-intensive, and limited in terms of overall throughput. Currently, there are many specialized methods that can be used toextract pure biomolecules, such as solutionbased and column-based protocols. Manual method has certainly come a long way over time with various commercial oﬀerings which included complete kits containing most of the components needed to isolate nucleic acid, but most of them require repeated centrifugation steps, followed by removal of supernatants depending on the type of specimen and additionalmechanical treatment. Automated systems designed for medium-to-large laboratories have grown in demand over recent years. It is an alternative to labor-intensive manual methods. The technology should allow a high throughput of samples; the yield, purity, reproducibility, and scalability of the biomolecules as well as the speed, accuracy, and reliability of the assay should be maximal, whileminimizing the risk of cross-contamination. Copyright © 2009 S. C. Tan and B. C. Yiap. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
1. Introduction of Biomolecules Extraction
The extraction of biomolecules, DNA, RNA, and protein,is the most crucial method used in molecular biology . It is the starting point for downstream processes and product development including diagnostic kits. DNA, RNA, and protein can be isolated from any biological material such as living or conserved tissues, cells, virus particles, or other samples for analytical or preparative purposes . Two categories that involved in purifying DNA includethe isolation of recombinant DNA constructs such as plasmids or bacteriophage and the isolation of chromosomal or genomic DNA from prokaryotic or eukaryotic organisms . Generally, successful nucleic acid puriﬁcation required four important steps: eﬀective disruption of cells or tissue; denaturation of nucleoprotein complexes; inactivation of nucleases, for example, RNase for RNA extraction andDNase for DNA extraction; away from contamination . The target nucleic acid should be free of contaminants including
protein, carbohydrate, lipids, or other nucleic acid, for example, DNA free of RNA or RNA free of DNA . Quality and also integrity of the isolated nucleic acid will directly aﬀect the results of all succeeding scientiﬁc research . On the other hand, RNA is an unstablemolecule and has a very short half-life once extracted from the cell or tissues . There are several types of naturally occurring RNA including ribosomal RNA (rRNA) (80%–90%), messenger RNA (mRNA) (2.5%–5%) and transfer RNA (tRNA) . Special care and precautions are required for RNA isolation as it is susceptible to degradation [3, 6]. RNA is especially unstable due to the ubiquitous presence...