expiry date 32P dCTP radioactive probe? - (Jan/16/2008 )

Hi all!

Does anybody know what the expiry date of 32P dCTP radioactive probe is, which I want to use for Northern Blot, since I am new in the field of radioactive stuff I would like to hear your opinion!

Thanks in advance!

Merel

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The fresher the better. After two weeks we usually double the amount we use, after 1 month definitely order new.

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the half life of 32p is about 14 days. after a month you are left with less than 25% of the original radioactive concentration. depending on what you are using it for it will have degraded too far for it to be useful.

so, follow smu2's advice (although, it would be better if you could use it up within the first two weeks).

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The half-life of 32P is 14.3 days. That means that every 14 days the signal you got off the probe is half of what you would have seen two weeks prior. Depending on how old your probe is, it may be impossible to detect a signal. I generally won't use 32P that is a month old but it all depends on your probe (how many 32P present) and how much you anticipate will bind the membrane. It may be worth an initial experiment but anticipate you may need to make a freshly labeled probe.

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