Fingerprinting and DNA Extraction

Fingerprinting and DNA Extraction

Year 6 pupils played Forensic Detectives for the day – uncovering fingerprints and extracting DNA, as part of their active learning project on ‘Identities’.

The fingerprint workshop was led by Mrs Burrows, a forensic technician from Greater Manchester Police, who explained how important it was that a crime scene is kept clean and untouched and not ‘contaminated’.

Pupils therefore ensured they were appropriately dressed with their own white forensic suit, mask and latex gloves, before watching a demonstration of the techniques used to find fingerprints at a crime scene.

Pupils were shown how to carefully dust the glass bottles and containers with a special black fingerprint powder, brushing over the area to reveal a fingerprint. They were each given various objects and tasked with investigating their own crime scene.

Mrs Burrows explained how unique fingerprints are and how they can be ‘lifted’ from objects at a crime scene, even from articles of clothing or plastic carrier bags by using super glue. The fingerprints are then compared to all those held on a huge fingerprint database, used by the police to identify criminals.

Pupils used black ink pads to take a print of their own fingerprints to examine how unique their own pattern was.

Meanwhile, as these crimes were being solved by the forensic fingerprinting team, Mr Coldwell had set up his own DNA extraction laboratory.

To demonstrate the process, Mr Coldwell asked the Year 6 pupils to extract the DNA from a piece of Kiwi fruit. He said: “Sometimes we forget that fruit are living things, but right inside the nucleus of each cell of every piece there is tightly coiled DNA.”

Saarah Khan explained the process:

“First you put some of the fruit in the bottom of a test tube and mash it up. Then you put some salt in and washing up liquid then added hot water.

“After about ten minutes you sieve the mixture and put the green liquid into another tube. When this is cold the teacher adds some Ethanol and all the DNA floats to the top.”

She added: “I really enjoyed doing this, but it would have been even better if we could do it with some real blood.”