By Yolanda Smith, BPharm
Recombinant DNA (rDNA) has many uses in the society of today, from research and biotechnology to the medicine stocked on the shelves of pharmacies. The ability to manipulate the creation of DNA with technology has proven to be useful in various applications, as outlined below.
The process to manufacture cheese usually relies on an enzyme called rennet, which contains chymosin. Traditionally, this substance is taken from the stomach milk-fed cows to manufacture cheese. However, recombinant DNA of chymosin has been in use since 1990, and is genetically and structurally identical to the original enzyme, but can be produced in larger quantities and a lower cost.
A specific variety of rice, golden rice, is genetically engineered with recombinant DNA to express enzymes that promote B-carotene biosynthesis. At present this is still in the process of passing regulations, but has the potential to reduce prevalence of vitamin A deficiency worldwide.
Diabetic patients often require injections of human insulin to help control levels of glucose, as they have lost the ability to regulate blood glucose effectively. Using rDNA to create human insulin rather than obtain it form animal sources allows their widespread use across the pharmaceutical industry.
Recombinant human growth hormone is used to support normal growth and development for patients with malfunctions in the pituitary gland. This offers a noticeable benefit, particularly when contrasted to previously used methods of obtaining the hormone from cadavers, which could pose serious negative health effects.
Blood clotting factors play an essential role in the management of patients that suffer from hemophilia, a bleeding disorder involving lack of ability to produce enough blood clotting factor VIII for blood coagulation to function as normal. The ability to manufacture recombinant blood clotting factor VIII allows larger quantities to be used in practice and reduces the need for blood donation to obtain the factor naturally.
Hepatitis B is an infection of the liver that can be prevented with the hepatitis B vaccine. Recombinant DNA of the hepatitis B virus surface antigen is produced in yeast cells to be included in the vaccine. This is beneficial as the hepatitis virus does not proliferate in vitro and recombinant DNA provides a method to create the DNA needed to control hepatitis B.
Recombinant DNA has been used in the development of the most common diagnostic techniques for HIV.
- The antibody test uses a recombinant HIV protein to measure antibodies in the body that proliferate when there is a HIV infection.
- The DNA test uses reverse transcription polymerase chain reaction (RT-PCR) to detect presence of HIV genetic material. This technique was developed using rDNA of molecules and analyzing the genome sequences.
Some commercial crops, such as soy, maize, sorghum, canola, alfalfa and cotton, are grown with recombinant DNA that increases resistance to herbicides used in the agricultural process. Glyphosate is the herbicide known commonly as Roundup is widely used among farmers to help with weed control and recombinant genes in the agricultural crops allow them to grow without being affected by the herbicide.
Additionally, recent developments have enabled plants to express a recombinant form of Bt toxin protein usually produced by Bacillus thuringeiensis bacteria. This is naturally able to control insects threatening agricultural crops and has become a common practice in both gardening and farming. The long-term health and environmental effect of the recombinant gene is still undetermined and is a controversial issue.
Last Updated: May 4, 2015