Are paraffin or frozen (fixed) sections are better for IHC?
I’ve had great success in the past with frozen or vibrating microtome sections, and have been trying paraffin lately, but haven’t got any good results. Answer 1. Generally frozen sections are better for IHC because the antigenic content is well preserved (provided the tissue is snap frozen rapidly, preferably in isopentane, then stored at -70C). A “good” frozen section cut at about 5 microns should provide adequate morphology. The advantages of paraffin tissue blocks is that larger pieces of tissue can be used, and morphology is a degree better, storage is easier, etc. The disadvantage of paraffin blocks is the fact that the processing of the tissue (especially when preserved in common fixatives such as formalin or other formaldehyde- based solutions) cross-links certain proteins in and on the cells. Preatreatment to “unmask” cross-linked antigens is often essential. Antigen retrieval techniques include microwaving in citrate buffer and pressure cooker techniques. However, some antigen
I’ve had great success in the past with frozen or vibrating microtome sections, and have been trying paraffin lately, but haven’t got any good results. Answer 1. Generally frozen sections are better for IHC because the antigenic content is well preserved (provided the tissue is snap frozen rapidly, preferably in isopentane, then stored at -70C). A “good” frozen section cut at about 5 microns should provide adequate morphology. The advantages of paraffin tissue blocks is that larger pieces of tissue can be used, and morphology is a degree better, storage is easier, etc. The disadvantage of paraffin blocks is the fact that the processing of the tissue (especially when preserved in common fixatives such as formalin or other formaldehyde- based solutions) cross-links certain proteins in and on the cells. Preatreatment to “unmask” cross-linked antigens is often essential. Antigen retrieval techniques include microwaving in citrate buffer and pressure cooker techniques. However, some antigen
