Antigenicity, preservation

Target Retrieval Solutions from DAKO with pH 6.0 or pH 9.0 are well-suited for use on formalin-fixed, paraffin-embedded tissue sections mounted on glass slides. Compared with 0.01 M Citrate buffer, pH 6, the use of 0.001 M EDTA buffer, pH 9, significantly improves staining results for many antigens, preserves the morphology better and is especially useful in combination with the Dako EnVision visualization systems. 

L7. Leong, A.-Y.,Milios, J., andDuncis,C. G., Antigen preservation in microwave-irradiated tissues A comparison with formaldehyde fixation. J. Pathol. 156, 275-282 (1988). 

The dehydration process may also affect antigen preservation and various special dehydration procedures have claimed improved tissue antigenicity. Similarly, certain types of paraffin, celloidin, and polyethylene glycol have been shown to be useful for immunohistology (Larsson 1993). 

Microtissue arrays are a possible solution to the limited supply of control tissue. Microarray blocks allow the incorporation of 200-300 fine tissue cores into blocks that can be used for controls against a wide variety of antibodies and as the cores are small (0.5-1.5 mm diameter) much of the original tissue block remains preserved. Microtissue arrays should be used with the recognition that each core of tissue has been subjected to different fixation and processing so that the level of antigen preservation in each of the 200-300 tissue samples are different and by no means standardized. 

Pelstring RJ, Allred DC, Esther RJ, et al. Differential antigen preservation during autolysis. 

Anti-HBe Control, positive Human serum containing monoclonal antibodies to HBe antigen, preservative phenol (max. 1 g/L)... 

From large pieces of tissue, paraffin sections of fixed tissue or cryostat sections of fresh or fixed tissues are prepared. Many laboratories prefer cryostat sections since antigen preservation is superior and paraffin cannot be used for lipid-soluble antigens. Paraffin is removed from the sections with toluene or xylene and hydration through a graded series of alcohol baths. Further details can be found in textbooks of histochemistry or specialized literature (Culling, 1974 Nairn, 1976 and, Pearse, 1980). 

Zhang PJ, Wang H, Wrona EL, et al. Effects of tissue fixatives on antigen preservation for immunohistochemistry A comparative study of microwave antigen retrieval on Lillie fixative and neutral buffered formalin. J Histotechnol. 1998 21 101. 

Necrotic tissue Autopsy tissues may be suboptimal for immunocytochemical studies due to compromised antigen preservation. 

Fixative Structural Preservation Antigen Preservation Comments... 

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