What will testing blood at a crime scene prove?

Question

also how do they test for blood type?

Answer 1

Testing blood for its type at a crime scene cannot prove who was there, but it can prove who was not there. If there is enough blood to do DNA testing, then there is a chance to match a known DNA to the one from the scene. There are eight major blood types. A, B, O, and AB, each Positive and Negative. The blood types refer to protein markers on the surface of the cells. By mixing the blood cells with certain chemicals, we can detect the presence or abscence of those markers, and thus determine the blood type.

Answer 2

blood test will be taken for dangerous criminals. The blood found at the crime scene and is sent to the lab. The DeoxyRibonucleic acid (DNA) of the bllod is matched with the DNA records of the other victims.

I think the nitrogenous bases of the DNA structures are compared and then the segment of the long DNA's Purines and Pyramidines combination.

2 purines: adenine & guanine
2 pyramidines: cytosin & thymine

adenine grops with thymine and cutosine with guanine. a series of such arrangement is known as complementary pairing.

In the double helix of two polynucleotide, these arrangement is compared with the records. If the arrangment matches with the record, the search would narrow down, making it easier for detedtives to investigate.

Answer 3

If the scene has been cleaned, then testing for blood can tell investigators if that's where the person was attacked/killed.

If the investigators can collect blood, then they can try to extract DNA (WBCs - they have a nucleus) to test and match against potential suspects.

By testing for the proteins present that coat the surface of the RBCs. If you are type B, then a sample of your blood will 'clump' if it's exposed to type A blood because your immune system reacts to the 'foreign' substance.

Answer 4

Testing for blood helps people compare dna cells with suspects and stuff. A good example is CSI.

Answer 5

do not believe in DNA..... it truly is fairly humorous. i wager those 1000's of scientists are in simple terms making all of it up, huh? No, the law enforcement officials ought to care a lot less in case you've self belief in DNA or the guy int he moon. The Courts (and maximum prevalent people) believe that DNA no longer in person-friendly words exists, yet contains someone 'fingerprint' for each living being (plant and animal). So, you're out of success with the stupid concept. with assistance from the way, technological information does no longer position self belief in wager artwork. you want oxygen to stay. there is not any wager artwork that if I decrease off your oxygen, you'll die. Use some elementary experience.

Answer 6

You should watch forensic science on the Court Channel. People can be identified from their DNA (remember OJ? and that was many years ago). Also, blood type can be found from coagulation studies in different solutions.

Answer 7

it will prove who was at that crime scene if that person has DNA in the system already

so if you were involved in anything i suggest you dont give saliva to the cops/investigators or CSI if they suspect you in some way or how
so that means dont drink nothing they give just dont put your lips or tongue or hair on anything

plead the 5TH at all time's and the 4th when you are on the streets