Understanding DNA Technology

Without a doubt, DNA technology has revolutionized the world of science.  Scientific fields of biochemistry, genetics, biology and even forensics have been changed by the use of this powerful technology.  Deoxyribonucleic acid, otherwise known as DNA, is an organism's genetic material.  This technology has solved many mysteries behind evolution, diseases and even human behavior.


DNA technology is also being widely used to verify biological relationships and the identity of individuals living or deceased.  Major advances in DNA profiling have enabled DNA tests to be completed in just a short time.


There are many technologies used in DNA testing.  The most common of which are Electrophoresis,  Short Tandem Repeats (STRs), Polymerase Chain Reaction (PCR), Mitochondrial DNA Sequencing (mtDNA Sequencing) and Restrictive Fragment Length Polymorphism or RFLP.  A brief description of each technology is provided below.


Electrophoresis is a technique in separating DNA fragments according to size by introducing an electric field into the DNA molecule.  The DNA molecule is set on a viscous medium, referred to as the gel.  Longer and smaller molecules are separated because of their different abilities to pass through the gel.


Short Tandem Repeats (STRs) is a type of DNA analysis performed to examine specific areas in a DNA.  Each individual has differences in certain DNA regions.  These differences are used to ascertain the identity of an individual.


Polymerase Chain Reaction (PCR) is a technique used to create precise DNA replications.  Millions of replications are created thereby allowing DNA analysis to be performed on samples that are extremely tiny such as a couple of skin cells.  The sample though must not be contaminated by DNA of another source.


Mitochondrial DNA Sequencing (mtDNA Sequencing).  There are two types of cells in a DNA – nuclear DNA and mitochondrial DNA.  There are cases wherein a sample is too old and no longer has nuclear DNA.  mtDNA Sequencing is a technique used to recover mitochondrial DNA.  Forensics uses this type of technology on cases that have been unsolved even after so many years.


Restrictive Fragment Length Polymorphism (RFLP) DNA technology is one of the first technologies used in DNA analysis and is no longer widely used.

 RFLP analyzes different lengths of DNA fragments from the digestion of a sample with a restriction endonuclease enzyme.