Histotechs, Gayle Callis’ method of freezing nerves is illustrated in the DVD’s in the Muscle and Nerve packet I’ve been send around.  It shows a nerve in a flat plastic mold covered with OCT It stresses the fact that the liquid nitrogen must touch the bottom of the mold only. It must not get into the top of the mold. Freezing causes the OCT to contract.  Freezing from the bottom like Gayle says ands the DVD shows, keeps the contraction to only a small dent on the surface of the frozen OCT.  No problem.  This is shown in the DVD. It’s easily filled. If the liquid nitrogen gets into the top of the of the mold, the contraction will take place around the nerve making sectioning difficult indeed.

Athough DVD One band 9 shows how to patch gaps like these, there’s no reason to do so if you freeze the tissue carefully.

georgecole@ev1.net