The essential steps of DNA isolation are cell harvesting, lysis, protein degradation, and DNA precipitation.
Scientists use a spectrophotometer, which measures the intensity of a light beam passed through a sample as a function of its wavelength. By quantifying the output of wavelengths that are specific to nucleic acids or impurities, one can not only quantify the amount of DNA but also estimate the purity of the DNA sample.
It is an enzyme of bacterial origin that can recognize specific DNA sequences and cut it into segments at those locations.
Scientists can load DNA onto a gel in an electrophoresis chamber and pass electrical current through the gel. DNA carries negative charges, which causes DNA fragments to migrate towards the anode. However, the pores of the gel slow down larger DNA fragments relative to smaller DNA sequences, thus the pieces separate according to their size.
DNA isolation and profiling have been the fundamental first steps for many of the advancements in the past century; from identification of gene function, to revolutions of agriculture and forensics. In addition, these advancements recently paved the way for personalized medicine with improved treatment outcomes.