Main Uses: Latent and Bloodmarks on semi-Porous and Porous surfaces.
DFO is a reagent that (like ninhydrin) reacts with the amino acids present in fingerprints. The areas of application are the same: porous surfaces like paper, unpainted wood and the like.
A fingerprint developed with DFO is less visible in white light than after treatment with ninhydrin but with green light (about 530 nm), it fluoresces strongly. The fluorescence is viewed and photographed through orange or red filter (goggles).
Left: ninhydrin, middle: DFO, right: 5-MTN (toned with zinc chloride)
Fluorescence of DFO and 5-MTN (Excitation: 530 nm, Filter: OG590)
Fluorescence image converted to gray scale and inverted, levels changed
Fingerprint developed with DFO
Fluorescence of DFO developed thumbprint (Excitation: 530 nm, Filter: OG590)
Fluorescent image converted to gray scale, inverted, and image enhanced (levels)