The fingerprints of 11 persons who worked in the laboratory were applied to the following clean substrates: glass, metal (alloy metallic surfaces), and wood (cortex of hard wood). Experiments were conducted without hand washing and also immediately after vigorous handwashing with antiseptic soap. Fingerprints were applied at a standard pressure time of 30 seconds, and the fingerprints were submitted to morphological, quantitative, and type analysis. A total of 132 fingerprints were analyzed. Included in the description of research materials and methods are the recovery of fingerprints and extraction of DNA, the quantitation of DNA, the amplification and electrophoresis of DNA, sample genotyping, quality assurance/quality control, and statistical analysis. The research findings confirm that it is possible to recover DNA from fingerprints with quali-quantitative features suitable for positive identifications. The quantity of DNA recovered from an object after a single contact is limited to a few nanograms at most. The amount of DNA left in fingerprints probably depends on donor shredder status and on random factors rather than on scientific rules. Most DNA is lost during harvesting and extraction procedures, and an additional amount is degraded by apoptosis that affects epidermal corneal cells. Amplification can generate full or incomplete profiles in a high percentage of experiments. The authors advise that the recovery of DNA from evidence surfaces should be performed on the largest number of sites possible, as well as on those sites where the suspect is believed to have left fingerprints. There should be restrictions on the number of people who touch the evidence, and measures should be adopted that will prevent primary transfer from investigators and laboratory staff. A database with the genetic profiles of laboratory personnel should be established to allow for the detection of any such transfer. 3 figures, 4 tables, and 29 references