I met a problem when I was doing frozen section for mice melanoma tissue. Based on the confocal results I got as attached, seems like the cell structures are destroyed (looks like a network) and all cells are CD8 positive (T cell markers) and F4/80 positive (macrophage markers). Is there any potential reason for this? I used 10% formalin to fix the tissue overnight. Is there anything wrong with this fixation procedure?
For frozen section usually 4% PFA is a good fixative for overnight fixing followed by serial sucrose treatments. Sucrose treatment suppose to cryopreserve the cells/ prevent from damaging your cells from negative 80. If you do formalin fixing, then you usually have to do antigen retrieval (heat retrieval for example) in order to expose the antigens. Also, have you dried out your tissue during the IHC procedure? If you dry out your sections during IHC, tissue could look like this! try avoiding drying out your sections except the initial tissue adhesion into slide glass before washing off OCT from the tissue.
Hello
Has the tissue been fresh when you fixed it? Usually autolysis begins within an hour after being dissected.
Dendritic cells in cutaneus tissue may exibit T cell antigens.Thawing ice may have produced these artefactual lacelike changes observed in this study.
Did cryogenics induce apoptosis? Perhaps that explains the macrophages.