Lab 3 Report



Lab 3 Report

Lab Part 1: DNA Extraction: Biotechniques Virtual Lab

Deoxyribonucleic acid (DNA) isolation is an extraction process of DNA from various sources. Methods used to isolate DNA are dependent on the source, age, and size of the sample. Despite the wide variety of methods used, there are some similarities among them. In general, they aim to separate DNA present in the nucleus of the cell from other cellular components.

Isolation of DNA is needed for genetic analysis, which is used for scientific, medical, or forensic purposes. Scientists use DNA in a number of applications, such as introduction of DNA into cells and animals or plants, or for diagnostic purposes. In medicine the latter application is the most common. On the other hand, forensic science needs to recover DNA for identification of individuals (for example rapists, petty thieves, accident, or war victims), paternity determination, and plant or animal identification (Anderson, 1971, 489-498).

It is quite clear that the extraction methods have to be adapted in such a way that they can efficiently purify DNA from various sources. Another important factor is the sample size. If the sample is small (for example sperm, or a single hair) the method has to be different to the method used in isolating DNA from a couple of milligrams of tissue or milliliters of blood. Another important factor is whether the sample is fresh or has been stored. Stored samples can come from archived tissue samples, frozen blood or tissue, exhumed bones or tissues, and ancient human, animal, or plant samples (Anderson, 1971, 489-498).

The isolation of DNA usually begins with lysis, or breakdown, of tissue or cells. This process is essential for the destruction of protein structures and allows for release of nucleic acids from the nucleus. Lysis is carried out in a salt solution, ...