Basic green 4

Basic green 4 (Malachite green) is a cationic dye that is widely used as a bactericide in aquaculture and is also commonly used in laboratories for the determination of phosphates. Basic green 4 exhibits high cytotoxicity and carcinogenicity to mammalian cells, specifically shown by its IC₅₀ values of 2.03 µM for HEp-2 human laryngeal cells and 13.8 µM for Caco-2 human colorectal adenocarcinoma cells, and it can promote the development of liver tumors. The maximum absorbance wavelength is 621 nm^[1][2][3]. In Vitro: Basic Green 4 Measurement of Phosphate^[1]
(1) Preparation of Basic Green 4 storage solution: Slowly add concentrated sulfuric acid (60 mL, d=1.84 g/L) to 300 mL of water. Cool the solution to room temperature and add 0.44 g of Basic Green 4.
(2) Preparation of Basic Green 4 working solution: Add 10 mL of the dye to 2.5 mL of 7.5% ammonium molybdate, then add 0.2 mL of 11% Tween 20.
(3) Mix 1 volume of Basic Green 4 with 4 volumes of the phosphate sample.
(4) Let it sit for ten minutes, then measure the absorbance at 630 nm.
Basic Green 4 Fungal Inhibition^[2]
(1) Collect fish eggs using spawning mats in a pond environment and rinse off the mud with well water.
(2) Place the fish eggs in a petri dish and add Basic Green 4 at a concentration of 2 ppm for 60 minutes, or at a concentration of 10 ppm for 10 minutes.
(3) Discard the Basic Green 4 and rinse the fish eggs multiple times with well water.
(4) Place the fish eggs in a petri dish with clean, oxygenated water and incubate at 22°C (72°F). Observe the newly hatched fry for 24 hours to determine the survival rate after treatment. Each concentration test is repeated six times.