Agarose gel loading buffer: Difference between revisions
(local lab specific info removed) |
(Sucrose & xylene cyanol / bromophenol blue recipe) |
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==Recipes== | ==Recipes== | ||
The precise amount of dye is not important. However, it is crucial that you prevent overlay of dye and expected DNA size. For example, if you are expecting a genotyping band of 200-400nt, you shouldn't use bromophenol blue since it will obscure your product. In this case, you should use a larger dye like xylene cyanol. | |||
===Ficoll & Orange G === | ===Ficoll & Orange G === | ||
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Dissolve 1.5 g of Ficoll in 10 mL of deionized water. Add very small amounts of Orange G dye such that the loading dye is dark orange. Store in small aliquots at 4°C (room temperature is okay too). To use, add and mix 1/5th volume of loading dye to DNA solutions prior to loading into the wells of gels. | Dissolve 1.5 g of Ficoll in 10 mL of deionized water. Add very small amounts of Orange G dye such that the loading dye is dark orange. Store in small aliquots at 4°C (room temperature is okay too). To use, add and mix 1/5th volume of loading dye to DNA solutions prior to loading into the wells of gels. | ||
===Sucrose & xylene cyanol / bromophenol blue=== | |||
* 25mg bromophenol blue or xylene cyanol | |||
* 4g sucrose | |||
* H<sub>2</sub>O to 10mL | |||
Store at 4°C to avoid mould growing in the sucrose. 10mL of loading buffer will last for years. | |||
===Specific recipes=== | ===Specific recipes=== |
Revision as of 05:16, 20 April 2007
Loading dye is mixed with DNA samples for use in agarose gel electrophoresis. It generally contains a dye to assess how "fast" your gel is running and a reagent to render your samples denser than the running buffer (so that the samples sink in the well).
Material
Density
- Ficoll
- sucrose
Colour
- xylene cyanol (Sigma X4126)
- bromophenol blue (Sigma B8026)
- Orange G
Recipes
The precise amount of dye is not important. However, it is crucial that you prevent overlay of dye and expected DNA size. For example, if you are expecting a genotyping band of 200-400nt, you shouldn't use bromophenol blue since it will obscure your product. In this case, you should use a larger dye like xylene cyanol.
Ficoll & Orange G
- Ficoll 400
- Deionized water
- Orange G dye
Dissolve 1.5 g of Ficoll in 10 mL of deionized water. Add very small amounts of Orange G dye such that the loading dye is dark orange. Store in small aliquots at 4°C (room temperature is okay too). To use, add and mix 1/5th volume of loading dye to DNA solutions prior to loading into the wells of gels.
Sucrose & xylene cyanol / bromophenol blue
- 25mg bromophenol blue or xylene cyanol
- 4g sucrose
- H2O to 10mL
Store at 4°C to avoid mould growing in the sucrose. 10mL of loading buffer will last for years.
Specific recipes
Use
- Orange G: generally runs very fast (<100 bp)
- Bromophenol blue: purple, generally runs at ~500bp (depending on percentage agarose)
- Xylene cyanol: blue, runs at ~4kb