Some peroxidase-like enzymes in macrophages (probably catalase) and DAB-binding activities in erythrocytes (hemoglobin) are not blocked by formalin. The best way to block this activity was incubation with methanol-peroxide (99 parts of methanol-1 part of 30% peroxide) during de-waxing. 3% peroxide is also effective, but in some cases it causes extensive bubbling that can damage fragile sections. So, I am using methanol-peroxide for paraffin sections and stable peroxide buffer (buffer provided in DAB developer kits, such as Pierce metal-enhanced DAB kit) for cryo- sections.
Anatoli Gleiberman, PhD Director of Histopathology Cleveland Biolabs, Inc 73 High Street Buffalo, NY 14203 phone:716-849-6810 ext.354 fax:716-849-6817 e-mail: AGleiberman@cbiolabs<mailto:AGleiberman@cbiolabs>.com This communication may contain privileged information. It is intended solely for the use of the addressee. If you are not the intended recipient, you are strictly prohibited from disclosing, copying, distributing or using any of this information. If you received this communication in error, please contact the sender immediately and destroy the material in its entirety, whether electronic or hard copy. This communication may contain nonpublic information about individuals and businesses subject to the restrictions of the Gramm-Leach-Bliley Act. You may not directly or indirectly reuse or redisclose such information for any purpose other than to provide the services for which you are receiving the information. _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet