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Which tray would I choose for use with Ninhydrin for fingerprint analysis?

and…… what is ninhydrin?

Various solutions of Ninhydrin may be used to develop latent prints on porous surfaces such as paper, cardboard, and wood. Ninhydrin reacts with amino acids commonly found in latent print residue to form a purple compound, yielding latent prints visible in shades ranging from reddish-purple to brownish-purple.

There are a variety of techniques involved using ninhydrin and the tray comes into play at the processing stage:

It is recommended to apply Ninhydrin solution by painting or dipping. For dipping, glass, metal or plastic trays can be used. Camlab offer a variety of trays for this purpose




Metal, plastic or wooden tweezers or forceps can be used to move the paper items in and out of the tray of Ninhydrin. Immerse the item for a few seconds and remove it from the tray, allowing the excess liquid to drip back into the tray. To paint, hold a cotton ball with a pair of forceps, dip it into the Ninhydrin solution and lightly brush the surface to wet it. Do not scrub the surface hard.

Precautions should be taken to avoid contact with both the powder form and the liquid solutions of Ninhydrin. Nitrile gloves should be worn, as latex gloves deteriorate with some of the solvents used, most notably acetone. A dust mask and goggles should also be worn to prevent the chemical or solvent getting into the eyes. In addition, some of the solvents used are flammable and must be mixed and used in a fume hood, away from all sources of heat or spark. If using Ninhydrin mixed in a flammable liquid at a crime scene, a full-face breathing apparatus should be worn and avoid any source of heat or spark.

Camlab can provide all types of safety equipment for your needs, just click on the links highlighted to view the available items or speak to a member of our technical team on 01954 233125 for advice.