2 replies to this topic

[Dr_Rob]

I guess this would be more of peoples opinion rather than a definitive yes/no answer, but....

 

I'm doing ChiP with tissue that I have to dissect in very small batches once a day, then flash freeze until I have enough to do a ChIP. Problem is the liquid nitrogen I need to use to freeze them is often in short supply, and a pain in the ass to get, and it seems very wasteful to use an aliquot just to freeze one eppendorf every day. Same problem with the alternative of dry ice/EtOH.

 

However, I do have access to a -150'C freezer, my question is: do you think freezing my samples in the -150'C freezer would be ok for my ChIP samples? The samples are maximum <20ul in volume (I'm doing Drosophila larval wing discs), and when I tested it the sample froze in under a minute. But I don't want to waste a lot of time gathering tissue and freezing it this way if it's going to affect my abillity to ChIP.

 

Any ChIP experts care to give their opinion? Thanks!

[phage434]

You can flash freeze in a dry ice/ethanol bath, and then put it at -150, if dry ice is more easily available.

[Dr_Rob]

Thank you for your suggestion, and yes I will be trying dry ice when I can get my hands on it, but the fact that we have a freezer that is so available would save so much time and effort, so I'm wondering what the opinion on freezing using that method is.

 

Cheers