Greetings.
I saw at linked article, human gene 1 copy=3.3pg. but, I don't know concentration of 3.3pg single molecule DNA. so what's concentration of it? (in molarity)
Actually, I know, RNA work(qRT-PCR or cDNA synthesis) run by weight of RNA molecule...
https://www.researchgate.net/post/What_is_the_minimal_amount_of_DNA_that_can_be_used_for_a_qPCR_reaction/1
The molarity will depend on the volume that the DNA is dissolved in. Based on the numbers you provided (3.3pg / copy of the genome), the concentration will be given by the following formula:
[DNA] (in Molar units) = x / 3.3 pg / (6.022 x 1023) / y
where x is the mass of DNA in pg and y is the volume of mixture in liters.
It sounds like you are new to molecular biology. Do some background reading in an introductory biochemistry book about the difference between mass and molarity.
The 3.3 pg is the mass of the molecule. It does not have a concentration in molarity unless it's in a solution.
just to make it easy there is software,
@Katie A Clark thx
I am not newbie but I thought fair 'RNA work is weight', and, past, working with gDNA is weight. So I don't have to calculate n ug of DNA's concentration or reverse.I am in the laboratory past. In there, I researched arabidopsis but now I am working with manufactured oligonucleotide.
3.3 pg is the mass of a single haploid copy of the human genome. On average, every single-copy gene will be represented once. In reality, they are subject to random variations and will vary from 0 to a handful of copies from aliquot to aliquot.
At the 3.3 pg level you are operating in the concentration region where you can no longer consider your solution as homogeneous. I refer to this a the stochastic region and it extends up to concentrations of about 10 copies per aliquot. It's not a good region to be operating if you want consistent results.
It's well worth revising what you learned in chemistry at school about amounts of substance and concentration. Molecular biologists switch between micrograms, nanomoles, copies and genomic units, sometimes as concentrations (per ul) sometimes as absolute amounts, with gay abandon. One reason for this confusing mix of units is that many researchers have difficulty doing the conversions themselves. It's a skill that's well worth learning.
Note that many molecular biology products catalogues include information pages about just this kind of calculation.
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