Thread: Forensics & Idential twins

Friend suggested this one.

Lets say a sample of blood was found at a crime scene, if it belongd to one of a set of identical twins would there be any way you distinguish which twin the blood belonged to (in the lab)?

I suggested that maybe as the twins may have suffered from different diseases they would have different antibodies but thats a bit overcomplicated in a lab sense...

Any ideas or is it impossible!

I don't think you could from a sample of blood, If they were truly identical twins, they'd probably both be evil, so convict the pair of them!

Yeah thought that bout the blood (and didnt want to say bout the evil thing!)

Originally Posted by Robbie

Friend suggested this one.

Lets say a sample of blood was found at a crime scene, if it belongd to one of a set of identical twins would there be any way you distinguish which twin the blood belonged to (in the lab)?

I suggested that maybe as the twins may have suffered from different diseases they would have different antibodies but thats a bit overcomplicated in a lab sense...

Any ideas or is it impossible!

There ARE differences within the DNA, even in identical twins !!

What? Differences in expression?

Originally Posted by Robbie

What? Differences in expression?

Differences in code sequence.

No it would have to be the same, if they're identical they're both from the same zygote.

Originally Posted by leohopkins

Originally Posted by Robbie

What? Differences in expression?

Differences in code sequence.

would they have RFLPs? (restriction fragment length polymorphisms, if you didn't know...) i don't know whether they happen before or after development... or i could be way off here, maybe this doesn't even make sense...

While identical twins have the same genotype, they can vary greatly in their phenotype. By finding out differences in their nutritional habits and health, the person could be determined. Platelet count or something like that could be used to distinguish the twins.

Originally Posted by Keith

While identical twins have the same genotype, they can vary greatly in their phenotype. By finding out differences in their nutritional habits and health, the person could be determined. Platelet count or something like that could be used to distinguish the twins.

I mostly agree, the phenotype allows [for example] the parents of IT's to tell them apart, I managed to find this which should clear things up a bit...

I just typed "Forensic Science Identical twins" into google... easy eh?

http://forensic-evidence.com/site/ID/ID_Twins.html

Yeah the nutritional idea is interesting alright, it sort of goes back to my antibody idea; basing the result n the person's history.

Megabrain, I looked at the article but it doesnt really say how one can be distinguishes from the there by blood alone! There must not be one way of finding out except for these random mutations mentioned.

RFLPs, I'm supposed to know what they are! Ill get back to you when I read up on it properly!

Originally Posted by Robbie

Megabrain, I looked at the article but it doesnt really say how one can be distinguishes from the there by blood alone! There must not be one way of finding out except for these random mutations mentioned.

You should have read what was not there.... ie since the article is about identifying one twin, and there is no mention of blood, then clearly it is not thought practicably possible from blood alone! 8)