Question

explain genomic fingerprinting

Answer 1

In this context, genome fingerprinting or also called DNA fingerprinting is a useful method which is mainly used to identify specific patterns of an individual.

As you know, every cell in our body contains DNA. Between two human, the DNA is the same in 99.9%. However, that 0.1% is what make us unique from one to another and that is what we determine using genome fingerprinting. This small percentage contains something called minisatellites which are short sequences composed by 10 to 60 base pairs of repetitive DNA that varies from on individual to another.

DNA fingerprinting allows us to detect minisatellites in each individual, remember that each individual posses a determined pattern of minisatellites.

In order to determine these sequences, the first thing that we need is a human sample (mostly blood). After that, we treat the sample with restriction enzyme which are able to cut the DNA, producing millions of small fragments of DNA. Once we obtained these fragments, we will separated them using a gel electrophoresis where fragments will be separate according their size.

The fragments on the gel will be transferred to a nylon membrane where they will be unzipped, producing a single strand DNA which will be in contact with minisatellites probes that attach to their complementary sequences. These probes will be observed under X rays. Each individual will have a specific pattern of minisatellite probes.