The gel is placed in a colourless liquid and electrodes are attached to the gel equipment, and a power supply is turned on.
By putting the liquid DNA fragments in the hole at one end and passing an electric current through the gel, the DNA fragments move into the gel with the electric current.
The enzyme takes a few hours to cut at all the places it can in the DNA strands.
Separating the DNA fragments on a gel The gel is like a sieve, in that it separates the different sizes of DNA fragment generated by cutting up the DNA.
What separated DNA fragments look like under ultraviolet light – a smear.
Picture is orientated like the picture above – the holes are by the labels.
Identification of cultivars and selections, pedigree analysis, estimation of genetic relatedness and genome mapping — all of these objects are achieved with various methods of DNA fingerprinting which can distinguish even closely related genotypes.
Initial results were obtained by a variation of the well-known RFLP-technique (Restriction Fragment Length Polymorphism): hybridization of restriction enzyme-digested DNA samples with hypervariable minisatellite DNA probes.
The DNA is stored, dissolved in essentially water, in a small plastic tube and kept in a fridge until ready for the next stage.
Cutting up the DNA Freshly extracted DNA in water is quite sticky, because the DNA strands are very long.