Editing Size-exclusion chromatography (section)

==Applications==
The main application of size-exclusion chromatography is the [[fractionation]] of proteins and other water-soluble polymers, while gel permeation chromatography is used to analyze the molecular weight distribution of organic-soluble polymers. Either technique should not be confused with [[gel electrophoresis]], where an electric field is used to "pull" molecules through the gel depending on their electrical charges. The amount of time a solute remains within a pore is dependent on the size of the pore. Larger solutes will have access to a smaller volume and vice versa. Therefore, a smaller solute will remain within the pore for a longer period of time compared to a larger solute.<ref>{{cite journal | vauthors = Brooks DE, Haynes CA, Hritcu D, Steels BM, Müller W | title = Size exclusion chromatography does not require pores | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 97 | issue = 13 | pages = 7064–7 | date = June 2000 | pmid = 10852951 | pmc = 16499 | doi = 10.1073/pnas.120129097 | bibcode = 2000PNAS...97.7064B | display-authors = 3 | jstor = 122767 | doi-access = free }}</ref>

Even though size exclusion chromatography is widely utilized to study natural organic material, there are limitations. One of these limitations include that there is no standard molecular weight marker;<ref name="Müller 4867–4872">{{cite journal |vauthors=Müller MB, Schmitt D, Frimmel FH |date=1 Dec 2000 |title=Fractionation of Natural Organic Matter by Size Exclusion Chromatography−Properties and Stability of Fractions |journal=[[Environmental Science & Technology|Environ Sci Technol]] |volume=34 |issue=23 |pages=4867–4872 |bibcode=2000EnST...34.4867M |doi=10.1021/es000076v}}</ref> thus, there is nothing to compare the results back to. If precise molecular weight is required, other methods should be used.