problem on removing coverslip for FISH after liquid N2 freezing - when it's still frozen or after thawing? (Jan/25/2010 )

Hi dear,
I am doing FISH these days. But I don't know how to remove coverslip after freezing the glass slide in liquid N2. I found it difficult to remove the coverslip when it was still frozen but when tried to remove it after thawing it always moved. can someone help? Thanks greatly.

Moreover, the protocol says to drop 200ul hybridization buffer onto the slide and to keep it at 42oC overnight. I wonder whether such a long time incubation would cause the buffer to dry out? Is it needed to film the slide or just cover with a coverslip being OK?

Many many many thanks!

The best way I found was to gently put the edge of a scalpel blade under the side of the slide and then flick it off. Sometimes it breaks but it's very fast compared to waiting for it to thaw.