Top Tips: Using the Crime-lite X to Visualise Fingermarks Treated with 1,2-Indandione
Why do we treat fingermarks with indandione?
1,2-indandione can be used to develop latent (invisible) fingermarks on porous surfaces, such as paper or cardboard. Latent marks consist of sweat and oils that are produced by the skin and are left behind during contact with a surface.
By targeting the amino acids that are present in sweat, latent fingermarks can be better developed and imaged. The advantage of using indandione over other techniques, such as ninhydrin, is that it fluoresces when exposed to certain wavelengths of light, making it easier to capture detailed images and achieve better contrast on patterned or multi-coloured surfaces.
Read on as we share three top tips on how to achieve the best results when visualising these marks with our powerful Crime-lite X!
1: Using the correct lighting and filters.
The Crime-lite X allows for the selection of specific illumination wavelengths. Indandione fluoresces well using the Green (480 – 560 nm) light source. Select the green light source using the left and right arrows on the top of the Crime-lite X.
To visualise this fluorescence, a filter whose cut-on wavelength exceeds the wavelength cut-off of the excitation light is needed. The 560 nm bandpass filter has been specifically designed for use with the 480 – 560 nm light source for the visualisation of the fluorescence produced by 1,2-indandione.
2: Use a Tripod or Arm!
Selecting the correct light source and filter is only helpful if the developed mark can be visualised and photographed at the same time. To ensure that the light source remains steady and consistent for image photography, mount the Crime-lite X on a tripod or arm. An adaptor will be needed between the threaded hole on the base of the Crime-lite X and the tripod.
3: Adjust the Lighting Intensity
The Crime-lite X allows for the control of lighting intensity. When the light source is active, use the centre button to toggle between low, medium and high intensity to find the perfect lighting conditions which fluorescence is achieved, but minute details are not obscured by excess fluorescence.
Learn more about the Crime-lite X
A complete ALS kit in a single light source, the Crime-lite X enables the examiner to seamlessly switch between White, UV, Violet, Blue, Blue/Green, Green, Orange, Red, and Infrared LEDs, to perform a comprehensive multi-spectral examination of a crime scene.