Details

Autor(en) / Beteiligte

• Poli, Mark A.
• Rivera, Victor R.
• Hewetson, John F.
• Merrill, Gerald A.

Titel

Detection of ricin by colorimetric and chemiluminescence ELISA

Ist Teil von

• Toxicon (Oxford), 1994-11, Vol.32 (11), p.1371-1377

Ort / Verlag

Oxford: Elsevier Ltd

Erscheinungsjahr

1994

Quelle

Elsevier Journal Backfiles on ScienceDirect (DFG Nationallizenzen)

Beschreibungen/Notizen

• M. A. Poli, V. R. Rivera, J. F. Hewetson and G. A. Merrill. Detection of ricin by colorimetric and chemiluminescence ELISA. Toxicon 32, 1371–1377, 1994.—A highly sensitive and specific ELISA was developed to detect ricin in biological fluids. The assay utilizes an affinity-purified goat polyclonal antibody to adsorb ricin from solution. The same antibody (biotinylated) is then used to form a sandwich, and avidin-linked alkaline phosphatase allows color development and measurement of optical density at 405 nm. Our routine assay uses a standard curve over the range of 0–10 ng/ml ricin, with accurate quantitation below 1 ng/ml (100 pg/well) in assay buffer as well as in a 1:10 dilution of human urine or 1:50 dilution of human serum spiked with ricin. Ricin measured in spiked samples demonstrated accuracy typically within 5% of the expected value in all matrices. The coefficient of variation ranged from 3–10% at 10 ng/ml to 8–25% at 2.5 ng/ml. Two variations on the routine assay were also investigated. First, lengthened incubation times and additional time for color development allowed accurate quantitation in serum dilutions as low as 1:2. Second, increased concentrations of biotinylated antibody and avidin-linked enzyme from 1:250 to 1:70 enhanced the sensitivity of the assay 10-fold, achieving a detection limit of at least 100 pg/ml (10 pg/well). The assay was also configured to a format based upon chemiluminescence, which allowed quantitation in the 0.1–1 ng/ml range, but was subject to slightly greater variability than the colorimetric assay.