Because the use of radioactive isotopes requires stringent safety precautions, an alternative methods, with at least equivalent sensitivity to the LIQUID SCINTILLATION COUNTING , are needed. Potential alternatives are ELISA methods which have been used to measure RISEDRONATE concentrations in serum.
The ELISA: direct competition between IBANDRONATE in the test sample and bisphosphonate conjugated to peroxidase (POD) for biotinylated anti-bisphosphonate antibody attached to streptavidine-coated tubes. When incubated with serum/plasma test samples, ibandronate becomes bound to the biotinylated antibody. The addition of bisphosphonate–POD conjugate and incubation with the POD substrate (the chromogen solution) results in a color intensity that is measured at 422 nm.
For more details see: Analytical methods for the quantification of ibandronate in body fluids and bone