Many people are familiar with the term “DNA,” which is the hereditary material in humans and almost all other organisms. Officially named deoxyribonucleic acid, it a molecule that carries the genetic instructions used in the growth, development, functioning and reproduction of all known living organisms and many viruses.
Not as well known outside the field of science is RNA or ribonucleic acid. RNA, a type of nucleic acid containing only one strand (DNA is primarily double-stranded,) provides the link between the genetic information through protein synthesis. Procuring high-grade RNA, which is accomplished through a process called RNA extraction (or isolation), is the first step for a multitude of molecular techniques often utilized in gene expression including microarray analysis, real-time polymerase chain reaction (PCR), digital PCR, northern analysis and cDNA library construction.
RNA Extraction
Using a powerful chaotropic salt solution, RNA extraction purifies RNA from biological samples by quickly disrupting cells or tissue to release the nucleic acids from the cells. These released RNAs are valuable in providing details on which genes are expressed (used to make products), to what degree the genes are active, how they work to regulate each other via small, regulatory RNAs and which structural RNAs (i.e. rRNAs, mRNAs and tRNAs) are produced.
RNA extraction can be very challenging due to the difficulty of isolating RNA that is intact. This is in large part because of ribonuclease (RNase) enzymes found in cells, enzymes which are copious in the environment and can swiftly degrade RNA. Therefore, it’s vital that it be done cautiously and in a timely manner.
Homogenization – Organic RNA Extraction
The disruption of cell and tissue samples, often achieved by homogenization, is a required part of extracting RNAs and preventing their degradation. In fact, samples aren’t guarded from RNA degradation unless they are entirely homogenized. Although homogenization is especially functional for use with soft tissues, the method used should be based on the sort of cell or tissue. For instance, plant and animal tissues, yeast and bacteria typically require more exacting disruption methods. Either way, the sample or tissue should be kept frozen until it is ready to be homogenized.
Utilizing homogenization for RNA extraction is especially beneficial because it enables processing to be effectively and repetitively processed in only seconds, thereby eliminating heat production. Its force and high pressure produce consistent and uniform samples, and it can process both small and large samples. Plus, homogenizers are scalable and compatible with many sample types, including those with tough cell walls.
