One of the ever-intriguing question most of us ask is ‘who we are’ or ‘where do we come from’? To answer this simple yet challenging question one should focus on to our genome. Dr. Svante Pääbo from his groundbreaking research have contributed immensely to our understanding of the human evolution for which he was awarded Nobel prize in Physiology or Medicine 2022. He and his team from years of research was able to shed light on human evolution which have created an entirely new field of genomics termed Paleogenomics.
In a molecular biology context, a genome refers to entire genetic information (DNA or RNA) of an organism. The genetic information is transcribed and translated to form a functional product (protein). This unidirectional transfer of information from DNA (or RNA) to RNA to Protein (genetic material to functional product) is the central dogma in molecular biology. This blog is the first in a three-part series that will focus on sample collection and handling. In the current blog (part 1) we will focus on sample collection and DNA isolation.
Two most common problems researchers face while handling their DNA samples are presence of other competing biological material and degradation. The presence of contaminants in samples leads to incorrect and inaccurate results. DNA is comparatively much more stable than RNA, however they also get degraded if not properly handled (presence of DNases) which will reduce the starting material for the researcher to work with. Therefore, it is essential to define and understand the sample that is being studied. Discover the wide spectrum of products for efficient sample collection offered by Nordic BioSite.
DNA isolation strategy varies depending on the samples being studied. The basis of an efficient DNA isolation begins with proper lysis of the sample. Some samples can be easily lysed or digested whereas others are a bit tricky. For example, the presence of cell wall in samples such as from plants, bacteria, fungi make lysis harder. Commonly used methods for lysis of such samples includes mechanical, chemical, or enzymatic disruption. However, ensure that the approach being used is suitable for downstream analysis as well. One can use a bead beater (or a vortex together with beads) to lyse samples. The limitation of such mechanical disruption is heat generation which can be counteracted by cooling the samples in ice bucket or even working in a temperature-controlled room. Incomplete lysis leads to low yield of DNA. With chemical or enzymatic digestion one can titer up/down concentration or time the samples are incubated thereby controlling sample lysis more efficiently. Furthermore, one should ensure that this approach is compatible with downstream processing or application of the DNA.
The Nobel Prize in Physiology or Medicine 2022. NobelPrize.org. Nobel Prize Outreach AB 2022. Mon. 10 Oct 2022. https://www.nobelprize.org/prizes/medicine/2022/summary/