Homework Question on DNA Profiling Procedure
- Explain the procedural steps inherent with DNA Profiling.
- How have PCR applications specifically revolutionized DNA testing?
Homework Answer on DNA Profiling Procedure
DNA profiling has undergone major transformation since its inception in the early years. Currently, the most modern process for DNA profiling involves the use of two different procedures. The first is the Restriction Fragment Length Polymorphism (RFLP) while the second is the Polymerase Chain Reaction (PCR) method. The latter is the newest method and has been used concurrently with the RFLP method with gradual shift towards the newer method (Easteal & Easteal, 1990).
In each of these methods, the first step in DNA profiling is the collection of samples. This may be voluntary such as in a case where a crime victim’s DNA is required for identification or accidental such as when a perpetrator leaves behind traces of his/ her DNA without knowing. In the RFLP method, the collection of samples is followed by the fragmentation of the long DNA strands by means of specific enzymes referred to as restriction endonucleases.
These cut the DNA strands along specific points on the strand resulting in several fragments, one of which contains the point of interest. This is analyzed using a piece of synthetic DNA probe. The fragment on which the probe has been bound can then easily be determined by including a chemical label in the form of a radioactive atom to the probe. The label emits a radiation which produces a visible image when exposed to x-rays. The identification of the segments of interest results in a pattern of bands called a DNA profile which can be used to identify and match DNA to existing criminal records (Roberts et al, n.d).