Forensic Science Basics

When you hear about police solving a crime you will often hear that they were able to “crack the case wide open” with the help of a DNA testing method. DNA testing methods are associated with solving crimes in many different cases including rapes and violent crimes, property crimes, missing people, and more.

What most people don’t know is that there are different DNA testing methods that may be employed based on the amount of material present and the information that needs to be derived from the testing.

DNA Testing Methods Used to Solve Crimes

When it comes to solving a crime and forensic scientist will generally look at the case and determine whether they should use RFLP or PCR DNA testing. These are two standardized types of tests and one is better for some situations than others.

For instance, if there is only a very little amount of DNA a forensic scientist isn’t going to elect to use RFLP DNA testing because this type of testing requires large amounts of testing material. On the other hand, if there is an old case and the DNA has degenerated over time RFLP may be the best option. PCR tests are often the test of choice because they are faster and easier than RFLP tests. Of course, there are other testing options, too.

RFLP is a much more accurate than PCR, unfortunately RFLP has been almost completely replaced by PCR. PCR is short for polymerase chain reaction and it is a reference to many different tests. This type of testing is very susceptible to errors in collection and testing practices, therefore tests with erroneous results are not uncommon. These tests simply increase the amount of DNA so there is more of it for typing.

A more common type of DNA test done today is the STR. This is a type of test that looks for short repeating DNA sequences. The test is done to distinguish the repeating characteristics of one person’s DNA to another to determine if DNA is the same as a sample or different.

In addition to this typing method there are also polymarkers, and DQ alpha locus. Each test can be used independent of the others or in conjunction with the others as the forensic scientist sees fit.

A forensic scientist will be able to solve crimes using these testing methods because with them they can copy and amplify DNA samples that they have and then easily compare and contrast them to a suspects DNA.

This can help to identify missing people that are found, murder victims, and even get DNA from the fingerprints of someone who has broken into a property or committed a crime.

A forensic scientist has all of these testing options at their disposal, which can help eliminate the possible suspects or individuals to a very limited and improbable number of people, effectively convicting or identifying someone based on the science of DNA alone.