Biomarkers leave gender clues at crime scene


© Shutterstock

Scientists in the US have unveiled details of a colorimetric assay1 that could provide an initial indication of a suspect’s gender during the on-scene stages of a forensic investigation.

Narrowing the pool of potential suspects early on in their investigations can give the police the upper hand. However, traditional DNA analysis requires laboratory conditions, sophisticated equipment and time. Rapid, simple, on-site analysis of blood left behind at a crime scene may provide investigators with a head start to quickly identify a group of possible suspects or rule out others.

Complementing their previous work,2 which used the enzyme biomarkers of creatine kinase (CK) and lactate dehydrogenase (LDH) to differentiate between blood samples from different ethnicities, Evgeny Katz at Clarkson University, Potsdam, and Jan Halámek at the University at Albany, State University of New York, have combined analysis of CK with another biomarker, alanine transaminase (ALT), to distinguish between male and female human serum samples. The levels of CK and ALT in the blood of males and females are known to show a small but significant difference. Using a multi-enzyme/multistep biocatalytic cascade, this small difference can be amplified and with the final step involving a coloured compound, a visual identification of gender can be made.

As with all biological samples, the levels of biomarkers will vary between individuals, and illness or disease may have a huge effect, leading to a third possible outcome: that no gender can be determined. However, Katz says, ‘the information about the health problems might be also important for the criminal investigation.’

Further development of the assay using real blood samples is currently underway, and will involve the challenge of moving from idealised, laboratory conditions to real life. As Jim Miller, emeritus professor of analytical chemistry at Loughborough University in the UK, explains, ‘the practical problems of dealing with labile biological materials at messy and complex crime scenes will need to be overcome before the method can be used routinely, but this quasi-quantitative approach to a qualitative analysis deserves further development.’ And while the assay is less sensitive and less specific than likes of DNA analysis, the advantages gained in terms of ease and speed may just be enough to compensate.

As the interest in the use of biomarkers for identification grows, it will be interesting to see how big a picture can be built from a drop of blood in the future.


Related Content

It's a bloody business

19 March 2015 Premium contentFeature

news image

Determining the role drugs and poisons may have played in death is the responsibility of forensic toxicologists. Nina Notman ...

A biochemical eyewitness

5 September 2013 Research

news image

Bioassay that recognises the blood of people with different ethnic backgrounds could aid crime scene investigators

Most Read

US government science institute's one time police chief linked to campus meth lab

31 July 2015 News and Analysis

news image

Explosion injuring a member of the National Institute of Standards and Technology's security force uncovered methamphetamine ...

(–)-Jiadifenolide

27 July 2015 Organic Matter

news image

BRSM wonders what makes a route so good it becomes the last total synthesis of a complex target

Most Commented

Scientist imprisoned over fraudulent HIV vaccine research

6 July 2015 News and Analysis

news image

Former Iowa State University researcher gets four-and-a-half years in prison for faking vaccine research funded by the NIH

Single polymer pill could deliver entire drug course in one go

27 July 2015 Research

news image

Flexible elastomer ring springs open to stay in stomach and could slowly release drugs over days