What makes up the thick bands in DNA fingerprinting?

Answer 1

Band thickness relates to the amount of DNA present at that size.

For example, if there were 5 fragments of 1000bp in length and 1 fragment of 2000bp in length, the band at the 1000bp spot would appear thicker than that at the 2000bp spot. This is because there are more fragments of DNA there.

A band may also appear thick if there are fragments of a very similar length - giving the appearance of one thick band. For example, if there were fragments with the lengths; 95bp, 105bp, 110bp and 120bp - they may all occupy a very similar space and so appear as one band.

Answer 2

The thickness and the intensity of the band depends on the amount of the DNA present and the the position of the band on the gel is determined by the size of the band. One could clearly understand this by a simple experiment. Take one DNA solution and separate them into two. Make one of the part diluted and leave other as such. Run both the solutions on the same gel in different lanes. One will see the band in same positions in one lane but one is brighter and other is faint. The reason being, the first solution has more DNA and it binds more EtBr.

Answer 3

The thick bands in DNA fingerprinting represent repeating sequences of DNA known as VNTRs (variable number tandem repeats). These VNTRs are highly variable among individuals, making them useful for identifying unique genetic profiles. The number of repeats at a VNTR locus determines the size of the band in the DNA fingerprinting pattern.

Answer 4

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