[Histonet] isopentane freezing of rat brain

Hector Gonzalez Pardo hgpardo <@t> uniovi.es
Fri Feb 11 10:50:38 CST 2005

I am using for the first time isopentane (2-methylbutane) to freeze my rat brains for histochemistry. However, when I do the histochemical staining, the tissue looks like "granulated" under the microscope, especially in the center. We usually immerse slowly (30 secs.) the entire brain on a weighing plastic boat in a glass vase containing isopentane chilled at -40 ºC. Then we wait for another 30 secs until it looks white on the surface, and we store it at -40ºC until sectioning using a cryostate. We used before a time-consuming procedure that worked, using cryoprotection with sucrose overnight, covering the whole brain with a cryogel (OCT compound / Tissue-Tek) and using a kind of freon-22 cooled by liquid nitrogen. Since we would like to continue using the easier isopentane procedure, does anyone know what are we doing wrong? Thanks! 

More information about the Histonet mailing list