DNA Purification
DNA purification is the process in the process of preparation of samples that eliminates enzymes, salts and other contaminants from lysed samples and PCR products before subsequent applications like cloning and sequencing. It also eliminates unwanted PCR-induced artefacts, such as primer dimers and nucleotides that are not incorporated. DNA purification in molecular biology research is an essential step that requires careful planning to achieve quality, reliable results.
There are numerous approaches to cleaning DNA. The standard DNA isolation techniques comprise a variety of steps, such as leukocyte separation or red blood cell lysis to remove inhibitors of heme protein of the PCR reaction. They also include deproteinization, RNAse treatment, ethanol and isopropanol precipitation, and then finally, DNA elimination. The majority of these protocols require the use of specially designed equipment, like an electrophoresis system as well as a biosafety cabinet due to the dangerous intercalating dyes used in the electrophoresis gel.
Other methods for DNA purification employ spin columns or 96-well filter plates to separate out contaminants by adsorbing them to the surface of the plate or column. These techniques can be very laborious, especially when dealing with large quantities of samples or when the columns have to be manually refilled with fresh reagents.
Dipsticks drastically reduce the number of sample processing steps to only three. They bind nucleic acid using an cellulose-based wax and then release them when water is present. This technique is particularly useful in low resource settings, such as remote sites or teaching labs. Its simplicity (30 s per sample) is a great fit for molecular diagnostic tests, such as detection of disease and genotype screening.