[Histonet] brain freeze artifact

[Terri Braud]

First of all, freezing spray should NEVER be used in a cryostat.  It produces dangerous aerosolized pathogens that linger in the air, just waiting to infect someone. There should be no exceptions.
As to the ice artifact problem,  not surprising to see this in brain since it is so fragile and often edematous.  Your best bet to eliminate freeze artifact is to "snap freeze" the tissue using the technique used in muscle biopsy samples.  A metal sample cup containing 2-Methyl Butane (Isopentane) is  suspended in Liquid Nitrogen, stirring until it becomes a thickened, white slurry.  The mounted tissue sample is immersed in this slurry to freeze, then placed in the cryostat to come up to cryostat temps before cutting.  That is the short and sweet version, and there are many published versions of the technique.  It is cumbersome, but produces no freezing artifact.
Best of luck, Terri

Terri L. Braud, HT(ASCP)
Anatomic Pathology Supervisor
HNL Laboratories for 
Holy Redeemer Hospital
1648 Huntingdon Pike
Meadowbrook, PA 19046
Ph: 215-938-3689
Fax: 215-938-3874
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Message: 3
Date: Fri, 16 Jul 2021 15:25:08 +0000
From: Bonello Dorianne M at Health-MDH <dorianne.m.bonello at gov.mt>
To: "histonet at lists.utsouthwestern.edu"
Subject: [Histonet] frozen section problem

Dear all,
We are experiencing freezing artifacts on our frozen sections. Basically, we are seeing cavity-like structures under the microscope, mostly elongated, especially when it's a frozen section on brain tissue. This is most probably happening due to ice crystal formation. We're not using cryospray, relying only on the cryobar boost function.
Does anyone has a solution to this problem please
Regards,
Dorianne Bonello
Allied Health Practitioner (MLS)
Histology Laboratory - Pathology
Health-Mater Dei Hospital