Some interesting Facts About Blood!
Did you know that the first successful blood transfusion was performed between dogs in 1665?
It was soon tried between humans with little success; puzzlingly it was occasionally successful in some cases but more often than not resulted in death.
The reason as to why, was not found for over 230 years later, in 1901.
Enter Karl Landsteiner, who noticed that blood became clumpy when the serum of another blood sample was added. With careful observation, the blood types: A, B and O were identified. AB was Identified sometime later. So the mystery as to why blood transfusions were not always successful, was finally solved.
Blood can only be transfused between two people of the same blood type. With one exception type, O. Blood type; O, lacks antigens so can be given to anyone.
Although we have mentioned A, AB, B, and O, we actually have eight blood types; a negative and positive version of each type.
This refers to the presence or absence RhD antigen on the red blood cells.
A person with the presence of RhD can’t donate to someone lacking it.
In the UK the most common blood type is O positive and around 2.5 million units of blood are transfused every year.
Your blood type is inherited, so before DNA profiling, blood type was used to give us some information about your genetic material. The O type is recessive and needs two O alleles to be present. Because of this, a man with the AB blood type could not father a child who has the blood type O.
As a result blood typing began to be used in court as evidence of paternity, and in forensics.
A landmark case of this was the 1943 case of Joan Barry who accused Charlie Chaplin of being the father of her child. His blood type compared to the child ruled him out as the father.
Blood typing for paternity only works with the recessive O and AB type. As type A and B could be carriers for an O allele, so without the detailed DNA profile there was no way to tell if the father was type O anyway whether he was the definitive father of the child. Blood typing could only be used to exclude suspects. This was the case in forensics, if blood evidence was found the blood type could be used to exclude potential suspects but never confirm their presence.
Stay tuned for our next blog post on blood spatter!