Gentian violet

Gentian violet (crystal violet, Methyl Violet 10B, hexamethyl pararosaniline chloride) is an antifungal agent, the primary agent used in the Gram stain test, perhaps the single most important bacterial identification test in use today, and it is also used by hospitals for the treatment of serious heat burns and other injuries to the skin and gums. Typically prepared as a weak (e.g. 1%) solution in water, it is painted on skin or gums to treat or prevent fungal infections. Gentian violet does not require a doctor's prescription (in the US), but is not easily found in drug stores. Tampons treated with gentian violet are sometimes used for vaginal applications.

Gentian violet is also known as Andergon, Aniline violet, Axuris, Badil, Basic Violet 3, Brilliant Violet 58, Gentiaverm, Hexamethyl-p-rosaniline chloride, Meroxylan, Meroxyl, Methylrosalinide chloride, Methyl Violet 10BNS, Pyoktanin, Vianin, Viocid, and Viola Crystallina.

Applications
Commonly used for
 * Tinea; e.g. Athlete's foot, jock itch, and ringworm
 * Candida albicans and related infections; e.g. thrush, yeast infections
 * Mouth ulcers

In forensics, gentian violet was used to develop fingerprints.

In body piercing, gentian violet is commonly used to mark the location for placing a tongue piercing.

Engineering students in Canada traditionally use this substance to dye their whole bodies purple in preparation for homecoming celebrations and frosh week. Additionally, Queens University's golden leather engineering jacket, also known as Golden Party Armour or GPA, is purpled using this dye.

Precautions
The Food and Drug Administration has determined that gentian violet has not been shown by adequate scientific data to be safe for use in animal feed. Use of gentian violet in animal feed causes the feed to be adulterated and in violation of the Federal Food, Drug, and Cosmetic Act. 21CFR589.1000

Gentian violet's worst common side effect is staining skin and cloth, but if used on ulcerations or open wounds it can cause tattooing. It is generally considered safe for use on children and breastfeeding mothers. It has even been applied to the mouth and lips of premature infants, and has a long history of safe use. Many have recommended it for thrush on the nipple, and La Leche League lists gentian violet as a possible alternative. However, in large quantities, gentian violet may lead to ulceration of a baby's mouth and throat and is linked with mouth cancer. Dr. Sears recommends using it sparingly. Gentian violet has also been linked to cancer in the digestive tract of other animals.

When using gentian in order to purple skin or jackets, care should be taken to mix only low concentrations of the crystal into warm water. This avoids the material attaining a golden hue. Additionally, jackets with a waterproof coating should be scrubbed lightly with a scrub pad, steel wool, or light grade sand paper before dyeing.

Popular culture
In Catch-22, the medics are portrayed as using gentian violet on feet and gums as a universal panacea. During the 1940's in the US, tub soaks made with water and gentian violet were "prescribed" as a cure for poison ivy, though its efficacy in such an application is unsubstantiated.