Improved double-antibody enzyme immunoassay for methotrexate.

  title={Improved double-antibody enzyme immunoassay for methotrexate.},
  author={M N Al-Bassam and Michael O'Sullivan and James W. Bridges and Vincent Marks},
  journal={Clinical chemistry},
  volume={25 8},
We report an enzyme immunoassay procedure for methotrexate measurement that takes less than 3 h to perform. beta-D-Galactosidase (EC from Escherichia coli was conjugated to methotrexate by means of the mixed anhydride reaction. Bound and free labeled drug were separated by a preincubated cubic complex of first and second antibody. The enzyme… CONTINUE READING