Picrosirius Red Staining

To make the Picrosirius stain:

• Make saturated aqueous picric acid: heat 2-3 heaping teaspoons picric acid in 500+ ml distilled water, then cool. We use a magnetic stirrer/hot plate. If yellow needle-like crystals are not present when cool, then temperature was not high enough, or more acid is needed. Try heating again. Note: dry picric acid not in solution is very dangerous (combustible), so keep wet! Drain liquid for stain; crystals may be used again.

• Add 0.1 gram sirius red F3BA per 100 ml

• Allow solution to stand for 24 hours.

• Stain should keep for a few months at room temperature, or 100 slides, whichever comes first.

• 250 ml are needed for proper staining procedure

Staining:

• Paraffin embedded, 5 or 10mm thick sections are stained as follows:

Histoclear #1 - 3 minutes
Histoclear #2 - 3 minutes
Histoclear #3 - 3 minutes
100% ETOH - 3 minutes
95% ETOH - 3 minutes
70% ETOH - 3 minutes
H2O Rinse - 10 minutes
PS stain - 90 minutes
70% ETOH - 3 minutes
95% ETOH - 3 minutes
100% ETOH - 3 minutes
100% ETOH - 3 minutes
Histoclear #4 - 3 minutes
Histoclear #5 - 3 minutes
Histoclear #6 - 3 minutes

Note: can add 0.2% Phosphomolybdic acid in DD H2O for 2 minutes with quick rinse after 10 minute water step above.