| Autor: |
M N, Al-Bassam, M J, O'Sullivan, J W, Bridges, V, Marks |
| Rok vydání: |
1979 |
| Předmět: |
|
| Zdroj: |
Clinical chemistry. 25(8) |
| ISSN: |
0009-9147 |
| Popis: |
We report an enzyme immunoassay procedure for methotrexate measurement that takes less than 3 h to perform. beta-D-Galactosidase (EC 3.2.1.23) 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 activity of the bound fraction was measured with o-nitrophenyl-beta-D-galactopyranoside as substrate. The standard curve covered the range 1 to 10 micrograms of methotrexate per liter. One microgram of methotrexate per liter inhibited binding of the tracer by 17%. The assay is specific for methotrexate in the presence of folinic acid (citrovorum factor), folic acid, tetrahydrofolic acid, and other methotrexate metabolities. Intra- and inter-assay CVs were less than 5 and 10%, respectively. Results obtained with this enzyme immunoassay method agreed well with those obtained with an established radioimmunoassay method. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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