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DNA Fingerprinting

Benefits & Limits of DNA Fingerprinting

Benefits of DNA Fingerprinting:


The most important benefit of DNA fingerprinting is that there is strong similarities shown between genetic fingerprints of parents and children.   This is a benefit because a child's genetic fingerprint is made up of half the father's genetic information and half of the mother's information.  This means that the bands of a child's genetic fingerprint will match the bands on both of their parents, making it possible to establish paternity and maternity tests. 


The above picture shows how a paternity test is used to match a child with their biological father.  It shows that the child was compared with his alleged father, and the test on the right shows the child's DNA matches the father's DNA. This means that the father on the right is his biological father, while the one on the left is not. 
Click to view larger.

Limitations of DNA Fingerprinting:


One of the main problems with the process of DNA fingerprinting is that the sample can be easily ruined.  The tiniest pieces of genetic junk can contaminate DNA samples, causing them to be useless.  Although DNA fingerprinting requires a good sample to work with, this problem can be solved by using the newer technique called PCR.  PCR can use extremely small samples of DNA and produce a much faster result.  But this also means the DNA samples that PCR uses are even more likely to be contaminated because of their size, as it is harder to find a small sample with hardly any contamination.  Another limitation of fingerprinting is that the procedure is so complex and hard to read the DNA patterns, that sometimes the juror finds the evidence almost invisible.


Although DNA Fingerprinting is a highly advanced process, there are still some things that it is unable to do.  In dogs for example, a fingerprint does not make it possible to determine if the animal is a carrier of a disease causing allele.  Also, a DNA fingerprint is unable to show a crossbreed in animals.  This is because second or third generation crosses cannot be seen by working backwards in a pedigree.  It may soon become possible to discover the crossbreed of dogs, although right now this is not possible.

An uncontaminated DNA blood sample taken from a crime scene. Click to view larger.

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