Basic Fuchsin–Picric Acid

for Elastic Fibers

Material	Amount
Basic fuchsin	0.5	g
Distilled water	500	mL

Material	Amount
Saturated alcoholic picric acid	12	mL
Acetone	1	L

A 10% Formalin variant is suitable. Paraffin sections at 5µ are preferred.

Bring sections to water via xylene and ethanol.
Place in basic fuchsin for 1-2 minutes.
Rinse with tap water, then acetone.
Differentiate briefly with picro-acetone until tissue is just decolorised.
Rinse with acetone.
Clear with xylene and mount with a resinous medium

The Brown and Brenn picric acetone usually requires weighing semi-dry picric acid. The amount in the saturated ethanolic solution specified above is very close to that and it is a much safer means of compounding the solution.
If you use the Brown and Brenn variant of the Gram stain, the counterstain solutions from that may be used.
Be careful not to overdifferentiate. Apply picric acetone until most of the red is just removed from the background. This takes only a few seconds. It is easy to overdifferentiate.
This method is not meant as a primary means of staining elastic fibres. It can be done very quickly, about 5-10 minutes, and may be useful when time is limited.
Nuclei are not stained.

Prior to handling any chemical, consult the Safety Data Sheet (SDS) for proper handling and safety precautions.

Personal observation, Bryan D. Llewellyn.
Brown, J H and Brenn, L, (1931),
A method for the differential staining of Gram positive and Gram negative bacteria in tissue sections.,
Bull. John Hopkins Hosp., v 48, page 69.