Acid fuchsine is prepared by sulfonating basic fuchsine using sodium bisulfite at elevated temperatures. The process involves dissolving, heating, sulfonating, cooling, filtering, and storing the resulting dye solution.

Steps to Prepare Acid Fuchsine from Basic Fuchsine:

Acid Fuchsin (Hungarian Red) is a chemical dye in water/acetic acid mixture, falling in hazardous category 2, 2A, if exposed, can cause skin irritation and serious eye damage. It is often used in histology and is part of Masson's trichrome stain.

Acid Fuchsin is prepared from basic fuchsin by the process of sulfonation. But, sulfonation results in the formation of a dye that is weaker than basic fuchsin at disinfecting Gram-negative and Gram-positive bacteria.

In forensics, acid fuchsin (Hungarian Red) is generally used to decipher footwear marks in blood, especially on non-absorbent surfaces like linoleum flooring, glass, and other similar smooth tops. The process involves fixation of the blood prints with 2% 5-sulphosalicylic (in water), before developing them with acid fuchsin. ALS (green light, 515-560 nm) can further enhance the visibility of details in the developed blood marks. But Hungarian Red is not the preferred choice for processing blood marks on absorbent substrates. Furthermore, the SOP should be strictly followed to collect DNA and/or other biological evidence, etc., well before processing with blood print with acid fuchsin.