10X Zinc Fixative is a Tris-based buffer with zinc ions for fixation of tissue for immunohistochemical staining.  Zinc fixation is an alternative to formalin fixation of tissue for paraffin embedded sections. 10% neutral buffered formalin fixes the tissue by cross-linking proteins, but may cause a conformational change or "masking" of the antigenic epitope leading to reduced or absent antibody reactivity.  Different antigen retrieval techniques can be used to unmask the epitope, such as with BD Retrievagen A and B solutions.  It is not possible, however, in some situations to retrieve the epitope and obtain optimal immunohistochemical staining.  In these situations, the fixation of tissue with IHC Zinc Fixative is recommended, as it is a milder fixative compared to formalin.  Zinc-fixed, paraffin embedded sections can provide for excellent immunostaining results for many different leukocyte markers with tissue morphology comparable to formalin-fixation.  Use of antigen retrieval techniques on zinc-fixed paraffin sections may even further enhance antibody reactivity in some cases. Investigators should note that some antigens may not be preserved by zinc-fixation and in these situations, the use of fresh frozen tissue for immunohistochemical staining is recommended.

(RUO)

Immunohistochemistry-zinc-fixed (Tested During Development)

Zinc based fixative

Development References(1) 1. Beckstead JH. A simple technique for preservation of fixation-sensitive antigens in paraffin-embedded tissues. J Histochem Cytochem. 1994; 42(8):1127-1134. (Methodology).