GENTIAN VIOLET

[ Return to: Main Page   ||  Non-Porous Surfaces  ||  Sebaceous Techniques  ||  Fluorescent Techniques  ||  Tape Surfaces  ||  Wet Surfaces  ]

Chemical Name:
GENTIAN VIOLET		 Surface Used On:
Non-Porous surfaces, especially the adhesive side of tapes.		 Sensitive To:
Epithelial skin cells, Sebaceous lipids & Proteins.
Development Color: Method to Record: Hazard: Protective Clothing: Fume Hood Use:

Purple
Not
Reagent Characteristics

Development Complete When:

Source of Error:

Incompatibilities:

Precautions:

Storage Container:

Safety:

Recommendations:

Similar Reagents


Sequential Reagents
(Not necessarily in this order.)



Abridged Reagent Sequence

Visual Examination
|
Forensic Light
|
*** Gentian Violet ***
|
Liqui-Drox
|
Forensic Light

 GENTIAN VIOLET FORMULA:
FORMULA A.

   1 ml Gentian Violet solution
1000 ml distilled water.


FORMULA B.

   1 g Gentian Violet crystals 
1000 ml distilled water.
PROCEDURE OF APPLICATION 

1. Pass the item through a Tray
containing the reagent solution
for 1 to 2 minutes.

2. Cold tap water rinse - 30 seconds.

3. View visually, or with a 
forensic light source between 
505 nm - 570 nm with red goggles. 

4. CLEARING SOLUTION:
 
 10 ml Hydrochloric acid in 
 90 ml of tap water. (10% soln.)


Ridge Detail Visualized by:

Visible chemical/stain reaction.
Forensic Light Source induced.


Reagent Applicabilities:

Tape surfaces
Non-Porous surfaces
Fluorescent technique


Other Chemical Name(s):

Crystal violet
Crystal violet chloride
Aniline violet
Basic violet 3
Bismuth violet.


Working Solution Shelf-life:

Indefinite
Process Summary:
This is a dye staining process using a water-based working solution. The evidence is repeatedly stained and rinsed until optimum development occurs. This reagent may be applied to surfaces that are contaminated with oils and grease.
Accepted Deviations:
The working solution may be re-used. The working solution may also be applied by brushing. The developed detail may be viewed under a forensic light source at 505 nm to 570 nm using red viewing goggles.
Supporting Reference Materials:
1. "A Modified Crystal Violet Application Technique for Black Electrical Tape", Journal Forensic Identification, Vol. 40, No. 3, pg. 148.
2. Minutiae Magazine, Summer Special 1994, Issue No. 24, pg.7.
3. "Chemical Formulas and Processing Guide for Developing Latent Prints", U.S. Dept. of Justice, pg. 47-48, 1994.
4. Advances in Fingeprint Technology 2nd. Ed., Lee, H.C. & Gaensslen, R.E., CRC Press, Boca Raton, FL., 2001.
5. Manual of Fingerprint Development Techniques 2nd. Ed., Home Office - Police Scientific Development Branch, White Crescent Press, Ltd., Luton, England, 2001.
6. Technical Notes, Lightning Powder Co. Inc., Salem, OR., 2001.

[ Return to: Main Page   ||  Non-Porous Surfaces  ||  Sebaceous Techniques  ||  Fluorescent Techniques  ||  Tape Surfaces  ||  Wet Surfaces  ]