[Histonet] Re: Processing frozen brain samples

[Teri Johnson]

Hi Valerie,

Why would you need to remove the sucrose? I would place the frozen blocks in room temperature fixative or buffer with one or two changes, especially if you have OCT that needs also to thaw.

Why fixative? You may want to consider adding additional fixation if the tissue was minimally fixed in the 4% PFA prior to freezing; the best paraffin processing starts with well fixed samples prior to exposure to alcohol, xylene and heated paraffin. Inadequate fixation time will result in having your sample complete its fixation in the dehydration alcohols. Not necessarily a bad thing if all your work is based on samples partially fixed in aldehyde, and partially fixed in alcohol. Much harder to standardize that IMHO.

Teri Johnson
Manager, Histology
Genomics Institute for
Novartis Research
Foundation
San Diego, CA
858-332-4752