In search of blood – detection of minute particles using spectroscopic methods

An examination protocol for rapid detection of remnants of blood particles on garments of suspects in bloody murder cases is described. Micro particles of blood are sampled along with fibres and hairs using the tape lifting method. The tapings are searched with a low power microscope for red particles with morphology similar to blood. Presumed blood traces are further examined using microspectrophotometry on the cut out piece of taping. The typical visible spectrum of haemoglobin is characteristic for blood. Alternatively Raman spectroscopy can be used to measure the characteristic vibrational spectrum of haemoglobin. At a later stage, these particles may be removed from the piece of taping in order to extract the blood and attempt to obtain a genetic profile.