Statistical Calculation (Help! is my reasoning okay!!)

Graham Dellaire dellaire at ODYSSEE.NET
Sat Jul 13 21:30:27 EST 1996

Hello all,

I am trying to estimate the odds of integrating into a given position in 
the genome of the mouse if considered a random event.  If I use a number 
of approx. 3 billion bps for the size of the genome (with 40 chrms) then 
the odds of targeting a single chromosome is 1/40 chms or 1/75 million 
bps.  Okay now if you arbitrarily divide the genome up into 1Mb units 
there are 3000 Mb in the genome or 3000 separate units to target.  If 
you wanted to determine the odds of integrating DNA into the same one Mb 
unit wouldn't the odds of that event be approx. 1/3000? So then 
targeting the same 100kb would be 1/30 000 and so on....

So to recap 1/40 for the same chms
and 1/3000 for the same 1Mb unit.

Am I leaving something out?  What else should I consider?  For some 
reason this seems way too simple.

Finally if I have a given frequency for integrating in a locus, and I 
want to find out if the frequency deviates from random, what test should 
I use?  

Thanks in advance for all help and suggestions

G. Dellaire

dellaire at

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