[Histonet] RE: Why use Calcium Chloride in Trypsin Antigen

[C.M. van der Loos]

Dear Merced Leiker,If I remember correctly Ca-ions are necessary for trypsin to perform its enzymatic activity. The use of EDTA in your buffer is therefore perhaps not such a good idea. Just use a Tris-HCl buffer pH7.8. The addition of CaCl2 is only needed for some highly purified types of trypsin. Crude types of trypsin powder contain enough Ca and doesn't need the addition of CaCl2.Hope this helpsChrisChris van der Loos, PhD
Dept. of Pathology
Academic Medical Center M2-230
Meibergdreef 9
NL-1105 AZ Amsterdam
The NetherlandsDate: Thu, 08 May 2008 15:14:59 -0400
From: Merced Leiker <leiker <@t> buffalo.edu>
Subject: [Histonet] Why use Calcium Chloride in Trypsin Antigen
Retrieval?
To: histonet <@t> lists.utsouthwestern.edu

Does anyone know why CaCl2 is used in trypsin buffers for retrieval of 
antigen in paraformaldehyde-fixed, paraffin-embedded tissue sections?  Is 
it really necessary?  Can I just use a Trypsin-EDTA solution we already 
have in the lab?

Merced M Leiker
Research Technician II
354 BRB (Lee Lab) / 140 Farber Hall (mail)
School of Medicine and Biomedical Sciences
State University of New York at Buffalo
3435 Main St, Buffalo, NY 14214