Using 20% glicerol solution?? you could put it in a flask witk the desired solution with 20% glicerol, put the flask in a expanded polystyrene cold box ( http://www.thermalshipping.com/images/productimages/epsbox.png) put it in a -80ªC. 48H later put it off the box and store it at -80ªc or beter in Liquid nitrogen....  

Dear Saeid Afshar,

I think that fixing in ethanol is sufficient. The attached paper can be useful for you.

Best regards and good luck in your molecular studies.

Hudson

Hi!

Fix it in ethanol 80%. That you should do it!

Cheers

Antonio