Not a blood test, but there is genetic testing. Generally it is categorized as genetic testing used for "paternal diagnostics." Basically these are services offered to couples to tell them what role genes might play in the health of a child or the risk during pregnancy. Included among these are the full blood-type genotypes rather than just the phenotype in order to predict certain possible blood-type mismatches (you know you're phenotype is A+ but you want to know if you have the genotype A+O-).
One service I can think of that would give you that information is 23andme. You'll probably have to look at the full results because the user-friendly results they give are somewhat limited. The full results though will contain the full genotypes you are curious about though. I'd suggest asking your doctor about what test they might recommend - particularly if you have insurance. You may be able to get a similar test done that way cheaper and have your doctor explain the results rather than sift through it yourself.
One service I can think of that would give you that information is 23andme. You'll probably have to look at the full results because the user-friendly results they give are somewhat limited. The full results though will contain the full genotypes you are curious about though. I'd suggest asking your doctor about what test they might recommend - particularly if you have insurance. You may be able to get a similar test done that way cheaper and have your doctor explain the results rather than sift through it yourself.
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Perform test crosses.
Mate with women who are phenotypically O-.
If any of your children are type O then you carry an O allele (i).
If any of your children are Rh- then you are heterozygous for the Rh factor.
Mate with women who are phenotypically O-.
If any of your children are type O then you carry an O allele (i).
If any of your children are Rh- then you are heterozygous for the Rh factor.