Blood Drug Testing

What is the difference between the various types of human blood?

For example, when testing for blood type, how does a scientist know if the bood is type A or type B?? Or any other type? Are there physical or visible differences?

Public Comments

1. With the ABO blood group the difference is what antigens are on the cell surface. A Blood group - "A" antigens B Blood group - "B" antigens AB Blood group - "A & B antigens" O Blood group - no antigens present When identifying a persons blood group they would isolate the red blood cells and test them with anti-serum. Anti-A, Anti-B, Anti-AB. If the cells clump up with any of the Antiserums that is the blood group on the cells. To confirm they then test the liquid part (serum) to known A, B and AB cells. ie. if you have A antigens you are typed as Group A and that means you have anti-B in your serum and that will react with B cells. If you have an antigen on your cells then you don't make the anti-bodies to that cell. There is no physical or visible differences to any of the ABO blood types.
2. Protein Markers. In simple terms, yes there is a difference in the microscopic levels(more like electron microscope". Protein markers are what you may pretend as a key card for a room in a hotel. These protein markers are checked by a "guard" very often. If the protein marker doesnt match, the "guard" cuffs 2 blood cells together and possibly making the blood to claught in the blood vessel. The A cannot donate to B because they are different A cannot donate to O because they are different same goes with B but O is interesting because it has no markers therefore it is compatible with all.
3. when typing blood we use reagents that are antisera for the particular blood group. when the blood is added to the antisera it forms clumps. these clumps are visible to the naked eye. there is Anti-A, Anti-B, Anti-AB, Anti-D (which is the Rh). the interpretation depends upon the reactions to these to determine the ABO and Rh type. This is called a forward type. A back type is done on the serum with reagent red cells that are A1 and B. without the reagents to differentiate all blood looks alike unless you are looking with an electron microscope. medical laboratories aren't generally equipped with these specialized scopes.