# DNA damage via radiation conversion.

## Main Question or Discussion Point

I've got a bit of a painful question. I'm looking at several different articles that mention radiation damage to DNA quantitatively, but they use vastly different ways of representing this damage.

So my question is, is it possible, first of all, to convert between umol/J (micromoles per joule) and SSB/bp/Gy (single stranded breaks per base pair (actually nucleotide) per Gray)? One would of course have to assume the type of radiation (gamma, in this case). Secondly, I'd be interested in some direction as to how this could be done.

Related Biology and Medical News on Phys.org
Okay, I really hope I'm not breaking the rules by replying to my own post (I read the rules, I didn't see it there, but I know some boards have that rule ... /sweat). I have something of an update to my original query, and I was hoping that the blanks could be filled in.

And I'm sorry that this is so ugly:

In the first case, we have a yeild of Single Stranded breaks in micromoles per Joule:

umol/J

To rephrase this in terms of SSBs, apply Avogadro Constant tremembering umol, not mol:

6.022x10^17 SSB/J

And that's as far as I get on this side of the problem. But there's another side of the problem (oh joy):

SSB/bp/Gy

Now, this phrasing is just unpleasant as we are dealing with single stranded breaks in a single stranded scenario. So if there's 1 SSB/bp, there's 1 SSB/2nuc (nucleotides).

SSB/2nuc/Gy

And 1 Gy = 1 J/kg. So it follows that:

SSB/2nuc/J/kg

or:

SSB/2nuc * kg/J

and since we want this to approach what we've got up top, I'm going to collect the SSB and J to rewrite:

SSB/J * kg/2nuc

soooooo, we're left trying to equate, or find a conversion factor for:

6.022x10^17

and

kg/2nuc

Is this possible?