Age estimation of blood stains using different analytical techniques and the in-situ identification of proteins using BCA

The issue of establishing a correct timeline in terms of body fluids has always been an important aspect in any forensic investigation. The techniques currently being used have all proved to work quite well but have certain limitations. One of the main problems with these techniques is their invasiveness to the sample in question. This is a major problem as, in most cases, the sample analysed is quite small and the destruction of it via the use of one technique can limit it being used for other key experiments, all of which are important for an investigation.

In this project, the aim was to present a collection of techniques that have been proven to be non-invasive on samples and at the same time, provide key information regarding the identity of the sample in estimating the age. Techniques such as Raman Spectroscopy, Colorimetry and Small Angle X-Ray Scattering were used to establish the identity and estimate the age of a stain. Results were obtained which showed that Raman

Spectroscopy and Colorimetry provided the most useful information regarding the body fluid used. Another aspect of this project was to develop a technique that could be used to identify the presence of proteins on crime scenes. Bicinchoninic Acid (BCA) was used for this part of the project along with copper sulphate. The results obtained showed that the presence of proteins could be identified but the results were not specific enough to describe what type of protein was being detected. More work needs to be done on this part as it has potential to be modified and become human specific by adding fluorescent probes that are human protein (skin keratin) specific and therefore can be used as an identifying tool in terms of evidence collection and processing it for DNA profiling.