What Is DNA testing?

DNA testing is also referred to as DNA profiling, it is a technique used by forensic scientist to achieve identification of people by use of their DNA profiles.DNA profile consist of encrypted numbers that can be used to identify a persons DNA makeup.DNA testing is mostly applied in criminal investigation and parental identification where there is a conflict of identity.DNA testing employs repetitive sequences that are variable in nature referred as variable number or tandem repeats.

History of DNA testing
It was first discovered in the year 1984 at Leicester University by Allec Jeffrey’s in England. DR Jeffrey made his genetic fingerprinting commercial in the year 1887.

DNA testing process
The individual DNA is taken i.e. reference sample using buccal swab method, this method is preferred as it allows less contamination of the samples taken. Samples that can be used in DNA testing include saliva, blood and semen taken from an individual to be tested.
A reference is made by analyzing the samples to come up with a DNA profile, other samples are analyzed for the purpose of comparison to indicate whether there exists a genetic match. The samplers for comparison are readily obtained from DNA databases that are set up at different specific locations in a given region or country.

Techniques employed in DNA testing.
RELP analysis
It was the earliest method to be used in DSNA testing, largely relied on restriction enzyme digestion, preceded by Southern blot. It involves use of enzymes with DNA probes to analyze loci of VNTR.
PCR analysis.
This process involves amplification of DNA sample ,was discovered in the year 1987 by Mulis and Faloona.
STR analysis
It employs the use of short tandem which are repetitive in nature.

AmpFLP
Is a technique which c uses PCR in amplifying DNA .It came into use in the year 1990 .It is a cheap method and hence popular in countries with low income levels.

Uses of DNA testing.
DNA testing is largely used in the identification of relationships in a given family, i.e. Sibling ship, maternity, farthernity and other kinships in a family.
Sperm and ovum during conception fuse to form an embryo with distinct genetic characteristic arising from both parents; this can be analyzed through use of DNA tests’
Junk DNA is the is used mostly for human identification as it carries special information that allows identification easily.
In an individuals gene make up there are copies which in two, one copy represents the mothers DNA while the other copy carries the father DNA.

DNA databases
There are many DNA databases that have been put up in different places of the world. They are largely government controlled but there are other which are private. A cold hit is a DNA sample that has been taken from a suspected criminal and after analysis through comparing with the DNA in the database matches with the criminal DNA recorded.

Partial matches in DNA testing.
They are matches that show sharing in every locus, the sharing is in at least one allele. It does not require familial search software in its analysis.

DNA based testing is one of the newest and highly sophisticated techniques in use today in the testing of genetic disorders through DNA examination, also known as genetic testing. Other genetic tests are in use today as well, such as biochemical tests for examining microscopic fluorescent chromosomes, some specific proteins and gene products such as enzymes. These tests are on some specific tissue and blood towards finding some genetic disorders with around 900 tests of this nature available.

There are many reasons why individuals might want to be genetically tested. This is done in case of a specific disease running through the family history, looking for unique symptoms that a genetic disorder might have and those concerned about passing to children a problematic genetic.


These tests include a number of techniques examining markers in proximity with the genes. For diseases such as sickle cell anemia and cystic fibrosis, direct testing can be done through the analysis of specific genes within an individual. If the gene is not easily identified although it could be found in a certain area of a chromosome, linkage analysis comes into use, also known as indirect testing. The testing is done through provision of extra DNA from a family member who has been affected, for comparison purposes. Apart from identical twins’ DNA, every person has a very unique DNA and genetic tests come in handy in DNA fingerprinting or individual identification.

Genetic testing is not a very simple process with the results depending on effective laboratory procedures as well as accuracy in the interpretation and analysis of the results. The tests are distinct in terms of sensitivity mostly in detection of mutations or the detection of patients with the disease or those who will get it. Even for physicians who have been trained, the tests result interpretation is complex and challenging, even for other specialists in the health care profession.
During the results interpretation of the genetic test, it is important to have in mind that false negative or false positive test results could be given. Specialized training is highly needed for the conveyance and analysis of information on carrying out genetic tests for individuals who have been affected including their kin.

Information drawn from all aspects of genetic testing has a huge effect on families and individuals. Apart from family and personal issues, susceptibility or genetic complications may have an effect on insurance and employment. This is why handling of the information is very critical.

Privacy of the test is important and individuals have the right to maintain it. This is because a number of genetic tests are highly encouraged or required for newborn babies and developing fetuses. In case the infant is ascertained to be a carrier, or showing an inherited disease, such findings have implications on insurability or even future employability of the person in the future.

Before genetic testing is done, informed consent or the obtaining of permission for the process to be done must be carried out. The individual must be informed on the alternatives, effectiveness, benefits and risks to testing for the full implications of genetic tests to be clear. Genetic information is highly confidential and access must be limited to individuals authorized to use it.