Http://www.lifetechnologies.com/de/de/home/references/ambion-tech-support/rna-tools-and-calculators/dna-and-rna-molecular-weights-and-conversions.html
Http://www.lifetechnologies.com/de/de/home/references/ambion-tech-support/rna-tools-and-calculators/dna-and-rna-molecular-weights-and-conversions.html
If you do not need to be very precise, you can consider one base-pair to be 650 daltons.
If you're looking at pure DNA, Nadine's site is a very good one and gives you all kinds of handy formulae etc. - can't top it!
However, there's a few things to remember depending on what you're trying to do:
- DNA extracted from cells is likely to have some protein still bound to it (histones mainly) unless really thoroughly purified by e.g. Phenol/Chloroform extraction.
- A lot of DNA may be positively or negatively supercoiled (wrapped around itself, like when you roll a rubber band in your fingers) - on a gel, DNA (especially circular DNA such as plasmids) will often run at a different mobility to that expected due to this.
- Depending on what organism you're getting your DNA from (and how precise you need to be), remember that DNA - and especially CpG islands - can be methylated, so may not have exactly the right molecular weight. If you're only looking at general weight then this isn't a problem, but something to keep in mind.
- Also (something I always do!) don't forget the 2'-OH if looking at RNA not DNA!
I hope those are some useful comments - I don't mean to be patronising and appreciate you may well know ALL of this already, but just thought I'd chip in my two cents.
Good luck with it,
Dan
- Badges
- Science topic
- Similar topics
- Biological Science
- Molecular Biology
- Biomolecules
- Nucleic Acids
- DNA