Editing Gel electrophoresis (section)

===Agarose===
[[File:Gel_electrophoresis_insert_comb.jpg|thumb|Inserting the gel comb in an agarose gel electrophoresis chamber]]

{{main|Agarose gel electrophoresis}}
Agarose gels are made from the natural [[polysaccharide]] [[polymer]]s extracted from [[seaweed]].
Agarose gels are easily cast and handled compared to other matrices because the gel setting is a physical rather than chemical change. Samples are also easily recovered. After the experiment is finished, the resulting gel can be stored in a plastic bag in a refrigerator.

Agarose gels do not have a uniform pore size, but are optimal for electrophoresis of proteins that are larger than 200 kDa.<ref name="Smisek1989">{{cite journal | last1=Smisek | first1=David L. | last2=Hoagland | first2=David A. | title=Agarose gel electrophoresis of high molecular weight, synthetic polyelectrolytes | journal=Macromolecules | publisher=American Chemical Society (ACS) | volume=22 | issue=5 | year=1989 | issn=0024-9297 | doi=10.1021/ma00195a048 | pages=2270–2277| bibcode=1989MaMol..22.2270S }}</ref> Agarose gel electrophoresis can also be used for the separation of DNA fragments ranging from 50 [[base pair]] to several megabases (millions of bases),<ref>{{Cite journal |last=Voytas |first=Daniel |date=May 2001 |title=Agarose gel electrophoresis |url=https://pubmed.ncbi.nlm.nih.gov/18432695/ |journal=Current Protocols in Immunology |volume=Chapter 10 |pages=10.4.1–10.4.8 |doi=10.1002/0471142735.im1004s02 |issn=1934-368X |pmid=18432695 |s2cid=39623776 |access-date=1 March 2023 |archive-date=2 February 2022 |archive-url=https://web.archive.org/web/20220202131116/https://pubmed.ncbi.nlm.nih.gov/18432695/ |url-status=live }}</ref> the largest of which require specialized apparatus. The distance between DNA bands of different lengths is influenced by the percent agarose in the gel, with higher percentages requiring longer run times, sometimes days.  Instead high percentage agarose gels should be run with a [[Pulsed field gel electrophoresis|pulsed field electrophoresis]] (PFE), or [[field inversion electrophoresis]].

"Most agarose gels are made with between 0.7% (good separation or resolution of large 5–10kb DNA fragments) and 2% (good resolution for small 0.2–1kb fragments) agarose dissolved in electrophoresis buffer. Up to 3% can be used for separating very tiny fragments but a vertical polyacrylamide gel is more appropriate in this case. Low percentage gels are very weak and may break when you try to lift them. High percentage gels are often brittle and do not set evenly. 1% gels are common for many applications."<ref>{{cite web|title=Agarose gel electrophoresis (basic method)|url=http://www.methodbook.net/dna/agarogel.html|work=Biological Protocols|access-date=2022-03-23|archive-date=11 October 2018|archive-url=https://web.archive.org/web/20181011023503/http://www.methodbook.net/dna/agarogel.html|url-status=live}}</ref>