nature of "radiolysis" of probes

[Michael L. Sullivan]

I have a question on the nature of "radiolyis" of P-32 hybridiazation
probes.  When people talk about probes breaking down due to radiolysis, is
that occuring because of

1) decay of the incorporated P-32 to S-32 results in breakage of the
phosphodiester bond in some way

2) the action of the emitted beta particals in the sample results in
fragmentation of the probe

3) a combination of the above two processes.

I'm mostly curious (but also have a more practical matter in mind about a
failed hybridization) and haven't really found the answer anywhere else.

Thanks,

Mike

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