# dna fragments - (Aug/01/2010 )

just wondering if anyone could help me find this information or direct me to pertinent papers.
-average weight of 100nt of human dsDNA (as well as the upper and lower limits in extreme cases)
-based on dna fragmentation following apoptosis, approximately how many fragments can be expected in 1ug of DNA (max and min as well)

thanks for any assistance, i really appreciate it!

-kay

-ramank-

Argh, I'm too lazy to make the calculation but here is a post I found that will help you.

"DNA is made up of four building blocks, called nucleotides. The molecular weights of
these four nucleotides (A,C,G,T) are not identical, so in routine work we usually
average the molecular weights of all four and go with 330 daltons per nucleotide in
DNA (=330 grams/mole of individual nucleotides). Since DNA is double stranded, i.e.,
one nucleotide pairs with a nucleotide on the
opposing strand, then we can say the average molecular weight of a nucleotide PAIR in
DNA is 660 daltons. Now you just have to multiply 660 daltons by the length of DNA you
are working with. For example, let us say a bacterial cell has a million (10E6)
nucleotide pairs per cell. So, 660 daltons/nucleotide pair times 1,000,000 nucleotide
pairs equals the DNA's molecular weight: 660 million daltons, or 6.6 x 10E8 daltons).
Mammals have about 1000 times more than this per cell.
Paul Mahoney, PhD"

As for the higher and lowe value, I think the 330 Da is sometimes replaced by 342 Da.

And I think that 1ug is 6.022173643e+17 Da, but I'm nost sure.
Anyone else??