Paraffin wax embedded tissues

Jaber, J.R. et al., Cross-reactivity of human and bovine antibodies in striped dolphin paraffin wax-embedded tissues, Vet. Immunol. Immunopathol., 96, 65, 2003. 

Mil. Mason, D. Y., Cordell, J., Brown, M., Pallesen, G., Ralfkiaer, E., Rothbard, J., Crumpton, M., and Gatter, K. C., Detection of T cells in paraffin wax embedded tissue using antibodies against a peptide sequence from the CD3 antigen. J. Clin. Pathol. 42, 1194-1200 (1989). 

N14. Norton, A. J., and Isaacson, R G., Lymphoma phenotyping in formalin-fixed and paraffin wax-embedded tissues II. Profiles of reactivity in the various tumour types. Histopathology 14, 557-579 (1989). 

Singh, N., and Wright, D. H., The value of immunohistochemistry on paraffin wax embedded tissue sections in the differentiation of small lymphocytic and mantle cell lymphomas. J. Clin. Pathol. 50, 16-21 (1997). 

Two biopsies were performed for evaluation of the light microscope appearance of formalin fixed paraffin wax embedded tissue. They both showed some epidermal thickening and concentric lamellae of stratum corneum within the follicular ostia (Figure 16.6). There were no other changes of note. 

Dowsett M. Comparison of new immunohisto-chemical assay for estrogen receptor in paraffin wax embedded breast carcinoma tissue with quantitative enzyme immunoassay. J Cfin Pathol 1994 47 900-5. 

For illustrative purposes, the method used by Morgan4 is described below. In this example, cells are re-suspended in agarose gel that is taken up in a 1 mL syringe (see Fig. 6.4), generating a cylinder of cells. The cylinder of cells can be treated like tissue and placed in wax which, in turn, can be cut and embedded in paraffin wax blocks for cutting on a microtome. 

Embed tissue samples in paraffin wax in embedding cassettes. 

Take 4 (minimum) to 16 (maximum) paraffin-embedded tissue sections mounted on the silanated slides, and place them into the 65 °C oven, and melt the paraffin wax overnight. 

Proteins can be detected in tissue sections or cell cultures using similar immune detection systems. Use of an antibody to detect specific proteins in tissues is called immunohistochemistry, whereas detection of proteins in cell suspensions is called immunocyto-chemistry. Tissues can be prepared by fixation and embedding in paraffin wax, or by rapid freezing in a compound that inhibits ice formation in the tissue, so as to preserve cell morphology. Some antibodies do not work well with paraffin-embedded tissues, probably because the antibody cannot access the antigen properly (133). The most common labeling system used for detection of the bound antibody is an enzyme-coupled secondary antibody that produces a color reaction... 

Tissue preparation consists of fixation, subsequent dehydration, and embedding in paraffin wax to provide a rigid matrix for sectioning. Tissues that are to be embedded in paraffin wax are first fixed to optimize preservation, a process that profoundly affects the morphologic and immunohistologic results. The ideal fixative for IHC studies should not only be readily available but also be in widespread use to maximize the range and number of samples available for... 

Human tissue should be fixed in 10% neutral buffered formalin and then dehydrated for embedding in paraffin. Paraffin is nonaqueous embedding medium, so the tissue blocks must have the water removed or be dehydrated. Dehydration is done in organic solvents such as alcohol, acetone, xylene, or toluene. After dehydration, the tissue blocks are embedded with liquid (warm) paraffin. When cooled, the wax embedded block is sectioned on a rotary microtome. Before immunocytochemistry can be performed on the resulting tissue sections, they must be rehydrated by processing with the same organic solvents back to water. Thus, the dehydration and rehydration steps are needed before immunohistochemistry. 

Larger specimens can be handled in two ways, depending on the thickness of the tissue. Frozen sections can be stained or, alternatively, very small tissue pieces can be stained then embedded in paraffin wax and sectioned. Paraffin embedding is described in section 7.3.1.1 (see Note 7). 

C. W. Meuse and P. E. Barker, Quantitative Infrared Spectroscopy of Formalin-fixed, Paraffin-embedded Tissue Specimens, Paraffin Wax... 

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