Answer:
You'll have to find that A- can only receive with A- and O-, O- can only receive with O-, B- can only receive with B- and O-, and then AB- can only receive from AB-, B-, A-, and O-.
Explanation:
I believe if you have every blood type sample individually under the microscope, you can take another sample of everyone's blood type and start with O- under the microscope and see how it reacts. If it breaks up and looks separated, it is not the correct receiving blood type, but if is flush and all the same dark red color that isn't broken up at all, then that blood type can be received by the person. The O- blood type can ONLY receive O-, so you will have your first match (two matches because each blood group is represented by two people). You will have to continue you this process and go through each blood sample to see if they match. You'll have to find that A- can only receive with A- and O-, O- can only receive with O-, B- can only receive with B- and O-, and then AB- can only receive from AB-, B-, A-, and O-.