We know each of human somatic cells bear 46 distinct chromosomes, so when we extract DNA from blood, for example, then we observe a single but uneven thick bad on agarose gel. All the chromosomes are not same in size, so I think it should show 24 separated bands if the whole genome is extracted successfully.
However, what do you know about it?
Its very difficult to separate DNA of the whole genome in agarose gel since
- too large size affects it's movement in the gel
- many of chromosomes will be fragmented during extraction
- some of the chromosomes additionally will be fragmented in the gel
Here is the link to similar topic with pictures of the gel
https://www.researchgate.net/post/How_are_we_able_to_see_DNA_extracted_from_whole_blood_in_agarose_gel_electrophoresis_when_human_genomic_DNA_size_is_in_billions_of_bps
Hi Syed,
chromosomes in all species are structural parts of the genome used for evolution and replication. Cell cycles follow some rules and the interphase step is the longest step. at this step the genome is not divided in chromosomes and DNA is given as the long chain as you know. indeed when extracting DNA from cells will always give you the long chain version that you'll see on low agarose gels.
see this paper (https://www.nature.com/scitable/content/a-the-appearance-of-dna-during-interphase-14668934).
the only way to produce cells with separated chromosomes will be in cell culture and blocking DNA in the mitosis interphase step, fix the cells and see them under microscopy.
on agarose gel, you'll observe one big band and a smear depending on the degradation degree of the DNA.
fred
when we do extraction some time there will be degradation. and some physical behaviour like vortex transfer of DNA from one tube to another can brake them into small fragments. and also high % of gel cant allow larger fragment of DNA into it.