HAPTO is a quantitative turbidimetric test for the measurement of
haptoglobin in human serum or plasma.
Anti-haptoglobin antibodies when mixed with samples containing
haptoglobin, form insoluble complexes. These complexes cause an
absorbance change, dependent upon the haptoglobin concentration of the
patient sample, that can be quantified by comparison from a calibrator of
know haptoglobin concentration.