Ninhydrin

• Porous surfaces
• 95% of fingerprints on paper are developed with the Ninhydrin technique
• delayed 24 hours - 10 days to develop
• reacts with Amino Acids
• Is cheaper than DFO
• Cannot use on items that have been wet (amino acids are water soluble)
• Previously referred to as Rheuman's Purple
• Develops Purple

3 Alcohol Ninhydrin options:

1. Acetone - dissolves ink
2. Methanol - dissolves ink
3. Heptane - do not inhale

3 Ways to Use Ninhydrin:

1. Spray bottle
2. Dipping - 3 to 4 dips into alcohol
3. Painting onto a surface

PROCEDURE:

1. Immerse in tray 5 seconds, spray or paint until saturated
2. Photograph after developed with green filter
3. Photograph under ALS with orange or red filter if required