Tissue sectioning microwave

Notes CA98°C, heating tissue sections in 0.05 % citraconic anhydride at 98° C for 45 min CAPC, heating tissue sections in 0.05% citraconic anhydride in a plastic pressure cooker using microwave oven for 30 min Low pH, heating tissue sections in acetic buffer of pH 1-2 for shorter time as described in the text Citrate, conventional citrate acid buffer 0.01 M at pH 6.0 with same heating condition of a plastic pressure cooker described above. 

Shi SR, Key ME, Kalra KL. Antigen retrieval in formalin-fixed, paraffin-embedded tissues an enhancement method for immunohistochemical staining based on microwave oven heating of tissue sections. J. Histochem. Cytochem. 1991 39 741-748. 

Bull JH, Harnden P. Efficient nuclear FISH on paraffin-embedded tissue sections using microwave pretreatment. BioTechniques 1999 26 416-422. 

Suurmeijer AJ, Boon ME. Notes on the application of microwaves for antigen retrieval in paraffin and plastic tissue sections. Eur. J. Morphol. 1993 31 144-150. 

Igarashi H, Sugimura H, Maruyama K, et al. Alteration of immunoreactivity by hydrated autoclaving, microwave treatment, and simple heating of paraffin-embedded tissue sections. APMIS 1994 102 295-307. 

The effects of microwave heating on the tissue sections that result in epitope retrieval are exceedingly complex. A full understanding of the actions of microwaves at the molecular level to facilitate epitope retrieval is lacking. At least two mechanisms need to be considered heat and kinetic energy of the oscillating electromagnetic field. Both possibilities are discussed below. 

MICROWAVE HEAT-ASSISTED IMMUNOFLUORESCENCE STAINING OF TISSUE SECTIONS... 

Double immunofluorescence labeling in conjunction with microwave heating can be used to visualize two markers at the same cellular location in routine formalin-fixed and paraffin-embedded tissue sections (Mason et al 2000). The primary antibodies are either monoclonal antibodies of differing isotype/subclass or antibodies from different species. Labeling is visualized on a conventional fluorescence microscope equipped with a cooled analog monochrome CCD camera (Model C 5985, Hamamatsu Photonics, Billerica, MA) and recorded using off the shelf personal computer hardware and software. Contrary to general belief, paraffin-embedded tissue sections do not show excessive nonspecific fluorescence. 

In some cases, the use of medium wattages (e.g., 450 W) is preferred over high-power microwave outputs (e.g., 700 W). This difference has been demonstrated in the ISH for detecting measles virus and chicken anemia virus in formalin-fixed, paraffin-embedded brain tissue (McMahon and McQuaid, 1996). In this study higher power outputs resulted in decreased sensitivity. Although the exact reason for this phenomenon is not known, it is hypothesized that optimal oscillation of dipolar molecules produces optimal thermal effects in tissue sections at medium wattages. 

Tissue sections (8 pan thick) are placed on Probe-on Plus slides and floated on autoclaved water on a hot plate (42°C) for 2-3 min to remove compression. The water is removed with a paper towel, and the slides are placed on a slotted glass staining dish on its side in the microwave oven. To adhere the sections, the slides are heated in a microwave... 

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