ABO blood typing utilizes a(n) test using known antibodies for antigens on the surface of red blood cells to determine the blood type of a human patient.

The ABO blood typing system is a method used to classify human blood based on the presence or absence of certain antigens on the surface of red blood cells. Here are the steps to determine the blood type of a human patient:

1. Collect a Blood Sample: A blood sample is taken from the patient. This can be done through a simple blood draw.

2. Prepare the Blood Sample: The blood sample is then prepared for testing. This usually involves separating the red blood cells from the plasma.

3. Add Known Antibodies: The prepared blood sample is then exposed to known antibodies. In the case of ABO blood typing, these would be Anti-A, Anti-B, and Anti-D antibodies.

4. Observe the Reaction: The blood sample is then observed for a reaction. If the blood cells clump together (agglutinate) when mixed with a certain antibody, it means that the blood cells have the corresponding antigen. For example, if the blood cells agglutinate when mixed with Anti-A antibodies, it means that the blood cells have the A antigen, and therefore the blood type is either A or AB.

5. Determine the Blood Type: Based on the reactions observed, the blood type of the patient can be determined. If there is agglutination with Anti-A and Anti-B antibodies, the blood type is AB. If there is agglutination with only Anti-A antibodies, the blood type is A. If there is agglutination with only Anti-B antibodies, the blood type is B. If there is no agglutination with any of the antibodies, the blood type is O.

6. Confirm the Results: To ensure accuracy, the results are usually confirmed by testing the plasma with known A and B cells (reverse typing). The results of the forward and reverse typing should agree.

This is a simplified explanation of the process. In a real laboratory setting, there are many more steps and precautions taken to ensure accuracy and safety.