1. Select an application method.
Tray immersion: Submerge item in D.F.O. for 30 seconds.
Spray application: Evenly spray D.F.O. with a squirt bottle and leave on item for 30 seconds.
2. Allow item to air dry inside a fume hood for 30 seconds.
3. Apply a second application of D.F.O. using one of the methods described above and allow item to air dry inside a fume hood again.
4. Heat item at 100°C in a heating chamber for 10 minutes.
5. Ridges will develop a reddish-pink color and can be captured using 1:1 photography.
6. View ridge detail using a forensic light source in the 495 – 550nm range with orange or red googles.
7. Capture ridge detail using 1:1 photography and an orange colored or 550 (BP 35) bandpass filter.
PRO TIP: A hair dryer, iron (dry), or heat press machine may be used if a heating chamber is not available.
REFERENCES
Technical Procedure for DFO (1, 8-Diazafluoren-9-one). Office of Indigent Defense Services. (2012, September 17). Retrieved July 21, 2021 from http://www.ncids.com/forensic/labs/Latent/Technical/DFO.pdf.