Microwaves and heat in aldehyde fixation: model experiments with bovine serum albumin.
Most model experiments concerning tissue fixation have used low concentrations of fixatives and proteins. Here, high concentrations (up to 32%) of bovine serum albumin (BSA) were reacted with formaldehyde (1-20%) and glutaraldehyde (0.5-4%). Gels were formed between 16% BSA and 10-20% formaldehyde at room temperature, but not with percentages of formaldehyde lower than 4%. Microwave application or heating in a water bath to 50 degrees C gave a gel from 1 to 20% formaldehyde. Sixteen percent BSA also gave a gel with glutaraldehyde from 0.5 to 4%. Cone and plate viscometry showed rapidly increasing viscosity at 4% formaldehyde and 16% BSA at room temperature. At 50 degrees C, gels formed at a low concentration of formaldehyde. Tissue fixation in which the local concentrations of protein may be in excess of 30% is probably more complete than in vitro experiments in which low concentrations of reagents have been used to permit subsequent spectrometry. This was confirmed by polyacrylamide gel electrophoresis of liver.
Hopwood
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Pathology Department, Ninewells Hospital and Medical School, Dundee, Scotland.
D000447:Aldehydes / Q000378:metabolism / Q000528:radiation effects*; D000818:Animals; D002417:Cattle; D004591:Electrophoresis, Polyacrylamide Gel; D005404:Fixatives / Q000378:metabolism / Q000528:radiation effects*; D005557:Formaldehyde / Q000378:metabolism / Q000528:radiation effects; D005782:Gels; D005976:Glutaral / Q000378:metabolism / Q000528:radiation effects; D006358:Hot Temperature; D006801:Humans; D008099:Liver / Q000737:chemistry / Q000528:radiation effects; D008872:Microwaves; D008956:Models, Chemical; D012710:Serum Albumin, Bovine / Q000378:metabolism / Q000528:radiation effects*
D000447:Aldehydes; D005404:Fixatives; D005782:Gels; D005557:Formaldehyde; D012710:Serum Albumin, Bovine; D005976:Glutaral