for Fibrin – Long Version
Lendrum, Fraser and others published several fibrin stains, the most well known being the Picro-Mallory. There are several variants of the method, some more complicated than others.
With this trichrome stain full and complete fixation is absolutely essential. Minimalist formalin fixation and quick processing will give poorly stained erythrocytes with red or orange tinges instead of the yellow they should have. Lendrum and coworkers specified about seven days fixation in formal sublimate followed by processing thoroughly, sectioning, degreasing with trichlorethylene for 48 hours, then refixing in picro-mercuric-alcohol. Adequate results can be obtained with thorough formalin fixation (24 hours), thorough processing (overnight), sectioning, followed by refixing in Bouin's fluid at 56°C for an hour or so. However, results are inferior to those obtained by the full procedure. It is also a method where experience is required for optimal results.
An acid resistant nuclear stain, such as Weigert's iron hematoxylin,
celestine blue-hemalum sequence.
|Dissolve ingredients and filter.|
|Acid fuchsin||1||g||or||Biebrich scarlet||1||g||or||Acid fuchsin||0.4||g|
|Acetic acid, glacial||1||mL||Acetic acid, glacial||1||mL||Lissamine fast red||0.2||g|
|Distilled water||99||mL||Distilled water||99||mL||Acetic acid, glacial||1||mL|
|Acetic acid, glacial||1||mL|
3 mm slices of tissue should be fixed in formol sublimate for one week. They should be paraffin processed with a schedule that thoroughly and completely dehydrates, then thoroughly cleared with xylene and infiltrated with paraffin wax. This process would normally take 48 hours or longer. Err on the side of completeness, and do not attempt to shorten the process. Avoid rapid fixation and overnight processing, especially with formalin fixatives, as this produces tissues that stain poorly even with secondary fixation such as Bouin's fluid at 56°C for an hour. Sections should be 3-5 µ thick.
Lendrum, A. C., et. al. (1962)
Studies on the character and staining of fibrin.
Journal of clinical pathology, v. 15, p. 401.
Last updated January 2019