The researches find that the new chip device that offers superior identification of miniscule blood residues for forensic applications. Criminologists use luminol to identify microscopic blood drops, as well as low hydrogen peroxide concentrations, proteins and DNA. These are all invisible to the naked eye but become visible through a chemical reaction known as “chemiluminescence.” Detecting biological residues using this method; is cost effective and advantageous since the detect signal does not depend on an external light source.
Miniscule blood residues
The BGU microfluidic chip not only increases the chemiluminescent intensity several fold; but also prolongs the glow time of luminol, enabling the detection of much smaller blood samples in a forensic scene. The chip device was developed by BGU Prof. Alina Karabchevsky; head of BGU’s Light-on-a-Chip Group; a member of the BGU Unit of Electro-Optical Engineering and the Ilse Katz Institute for Nanoscale Science and Technology. The innovation combines the use of luminol with gold or silver nano spheres in a specially designed microfluidic device that increases the detection limit by amplifying chemiluminescent light emission and facilitating imaging in the chip.
“Our findings open the door to new integrated microfluidic chips;” said Prof. Karabchevsky. “Practical implementation of this discovered effect will include further superior chemiluminescence-based sensors for forensic science, research in biology and chemistry; and no-source opto-chemical lasers. Identifying trace quantities of blood can increase the efficiency and accuracy of a forensic investigation of a crime scene but requires more sensitive detectors than those that are currently available. We are looking for partners to further develop this promising patented invention.
Trace quantities of blood
Netta Cohen, chief executive officer, BGN Technologies tests for the presence of haem using phenolphthalein and tetra methylbenzidine combined with thin layer chromatography. The sample is next analyse for blood protein using sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Positive results for both steps of the procedure confirm the presence of blood. The importance of control samples to test for interfering environmental constituents is emphasize.
Results of experiments designed to simulate the burial conditions of blood residues on artifacts are described. These indicate that the haem component of blood is relatively stable but the protein undergoes some degradation. This suggests that the detection of blood on artifacts may be difficult but it is feasible.
researchers have developed a new chip device that offers superior identification of miniscule blood residues for forensic applications. Criminologists use luminol to identify microscopic blood drops, as well as low hydrogen peroxide concentrations, proteins and DNA. These are all invisible to the naked eye but become visible through a chemical reaction known as “chemiluminescence.”