DNA Bioservices
ABO blood type calculator
The DNA Bioservices ABO blood type calculator can be used to predict possibilities of paternity.
The calculator is used to determine either:
- The ABO blood type of the child when the blood type of the mother and the father are known (top chart), or
- The ABO blood type of the father if the blood type of the mother and the child are known (bottom chart).
DNA Bioservices ABO Blood Type Calculator:
ABO blood types can be complicated to understand. This is mostly due to the fact that the 'O-type' antigen is masked by the presence of an A- or B-type antigen. This is explained in the following chart, showing the different the genotypes that make up the blood types.
| Genotype (DNA) | Blood Type |
| AO or AA | A blood type |
| AB | AB blood type |
| BO or BB | B blood type |
| OO | O blood type |
For example, two O blood type parents can produce a child with only O blood type.
Two parents with A blood type can produce a child with either A or O blood types.
Two parents with B blood type can produce a child with either B or O blood type.
One parent with A and another with B can produce a child with A, B, AB or O blood types. If one parent has A and another has AB, they can either produce a child with A, B or AB blood types. If one parent has A and another has O, they can either produce a child with A or O blood types.
Rh Positive (Rh+) and Negative (Rh-) Blood Types
The Rh (+/-) factor is inherited separately from the ABO blood types. Similarly to the masking effect of the O gene in ABO blood types, the Rh negative (Rh-) gene is also masked by the presence of a Rh positive (Rh+) genotype. Therefore, a person may have a Rh + blood type and can still have an Rh - gene (See the chart below). Furthermore, 2 parents with Rh + blood types can have a child with Rh - blood type.
| Genotype (DNA) | Blood Type |
| (+ , -) or (+ , +) | Rh + |
| (- , -) | Rh |
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