R.A.M. (Rhodamine 6G, Ardrox, and MBD) is a powerful fluorescent dye stain used to enhance the visibility of latent fingerprints. It's particularly effective on non-porous surfaces that have been previously processed with cyanoacrylate ester ("superglue") fuming.
Equipment
- Fume hood (Highly recommended) For safe mixing due to the solvents involved.
- Chemical-resistant gloves
- Lab coat
- Safety glasses or goggles
- Glass beakers and graduated cylinders
- Stirring rod
- Large amber glass storage bottle (1 liter)
- Spray bottle (optional, for application)
Ingredients for a 1-Liter R.A.M Solution:
- Rhodamine 6G: 1 gram
- Ardrox P133D: Approximately 1 gram
- MBD (7-(p-methoxybenzylamino)-4-nitrobenz-2-oxa-1,3-diazole): 1 gram
- Methanol: 20 ml
- Isopropanol: 10 ml
- Acetonitrile: 8 ml
- Petroleum ether: 950 ml
Mixing Procedure:
- Safety First: Work in a fume hood, don your safety gear (gloves, lab coat, glasses).
- Dissolve the Dyes:
- In separate beakers, dissolve Rhodamine 6G in methanol, Ardrox in isopropanol, and MBD in acetonitrile.
- Create Stock Solutions: Since these dyes come in powder form, it's sometimes easier to create smaller volume stock solutions that you then measure out for the final R.A.M mixture. This helps with accurate weighing of small quantities.
- Combine: In the large amber bottle, add the dye solutions, methanol, isopropanol, and acetonitrile as per the recipe.
- Top Off: Add the petroleum ether, bringing the solution to the 1-liter mark.
- Stir Thoroughly: Ensure the mixture is homogenous.
- Label and Date: Label the bottle clearly with "R.A.M.", the date of preparation, and any relevant safety information.
Latent Print Processing with R.A.M:
- Cyanoacrylate Fuming: The item must first be processed with cyanoacrylate fuming to create the white polymerized deposits that R.A.M. will target.
- Apply R.A.M.:
- Dipping: Smaller items can be dipped in a tray containing R.A.M.
- Spraying: Use a spray bottle for control and to target areas on larger objects.
- Rinse: Gently rinse excess R.A.M. with petroleum ether.
- Visualization: Excite the treated prints with a forensic light source in the 415 nm to 530 nm range (green light is often ideal). Wear orange goggles to view the fluorescence.
- Documentation: Photograph any developed fingerprints using an orange barrier filter on your camera.
Storage Requirements:
- Light Sensitive: Store R.A.M. in an amber bottle to protect it from light degradation.
- Cool Environment: A cool, dark place is ideal to maximize shelf life.
Shelf Life:
R.A.M. should have a shelf life of approximately 12-18 months when stored properly. It's wise to date your solution and test it on known prints periodically.
Important Notes:
- Ardrox P133D quantities can be slightly adjusted to achieve the desired level of fluorescence.
- R.A.M. works best on smooth, non-porous surfaces like plastics.
- Always consult your agency's safety protocols and chemical hygiene plan when working with R.A.M.