The indirect Coombs test finds certain antibodies that are in the liquid part of your blood (serum). These antibodies can attack red blood cells but are not attached to your red blood cells. The indirect Coombs test is commonly done to find antibodies in a recipient's or donor's blood before a transfusion. A test to determine whether a woman has Rh-positive or Rh-negative blood (Rh antibody titer) is done early in pregnancy.
Allele frequency, or gene frequency, is the relative frequency of an allele (variant of a gene) at a particular locus in a population, expressed as a fraction or percentage. Specifically, it is the fraction of all chromosomes in the population that carry that allele.
When there are two alleles at a locus, the convention is to use p to represent the frequency of one allele and q to represent the frequency of the other. Thus p, the frequency of the CR allele in this population, is 0.8. The frequency of the CW allele, represented by q, is 0.2.