Basic zinc carbonate was purchased from Glaxo Laboratories, while basic fuchsin and crystal violet were procured from Sigma–Aldrich32 and GenteelR liquid detergent was used as the surfactant solution. 20 individuals, both males and females, with variable donor capabilities, were asked for their consented groomed fingerprints for the study.
Latent fingerprints were developed on metallic spoon, aluminium foil and glass slide simulating metal body firearms, knives, door knobs, bottles etc. where there is higher probability of culprit leaving chance impressions. The fingerprints were impinged on selected non-porous surfaces. These were immersed in clean water for 45 days and their development through SPR composition was done every day. The experiment was conducted in summer season in Delhi, India when the temperature was 40–43 °C and relative humidity was 26–34%.
For evaluating shelf life, the composition was stored in glass beaker covered with an aluminium foil under ambient laboratory conditions. The test solution remained stable for about 50 days.