A semi-quantitative dipstick assay for microcystin
- 421 Downloads
An immunochromatographic lateral flow dipstick assay for the fast detection of microcystin-LR was developed. Colloid gold particles with diameters of 40 nm were used as red-colored antibody labels for the visual detection of the antigen. The new dipstick sensor is capable of detecting down to 5 µg·l−1 (ppb; total inversion of the color signal) or 1 ppb (observation of color grading) of microcystin-LR. The course of the labeling reaction was observed via spectrometric wave shifts caused by the change of particle size during the binding of antibodies. Different stabilizing reagents showed that especially bovine serum albumin (BSA) and casein increase the assays sensitivity and the conjugate stability. Performance of the dipsticks was quantified by pattern processing of capture zone CCD images. Storage stability of dipsticks and conjugate suspensions over 115 days under different conditions were monitored. The ready-to-use dipsticks were successfully tested with microcystin-LR-spiked samples of outdoor drinking- and salt water and applied to the tissue of microcystin-fed mussels.
KeywordsDipstick Immunochromatographic Toxin Microcystin Gold nanoparticles Lateral flow
This research project was supported by the "Otto von Guericke" e.V. AiF (Association of Industrial Research Organisations; AiF-No. KF0479001KMD3).
We thank Sartorius AG for providing material and equipment for the preparation of the dipsticks.
- 7.Mhadhbi H, Ben-Rejeb S, Cleroux, Martel A, Delahaut P (2006) Generation and characterization of polyclonal antibodies against microcystins - Application to immunoassays and immunoaffinity sample preparation prior to analysis by liquid chromatography and UV detection. Talanta 70(2):225–235CrossRefGoogle Scholar
- 10.Chandler J, Robinson N, Whiting K (2001) Handling false signals in gold-based rapid tests. IVD Technology 7(2):34–45Google Scholar
- 12.Chandler J, Gurmin T, Robinson N (2000) The place of gold in rapid tests. IVD Technology 6(2):37–49Google Scholar
- 19.Stückmann H (2007) Entwicklung immunchemischer Schnelltestverfahren. PhD Thesis, University of HanoverGoogle Scholar
- 20.Cuello AC (1983) Immunohistochemistry, International Brain Research Organisation. 1200Google Scholar
- 23.Hodgkinson JL, Steffen W (2001) Direct labeling of components in protein complexes by immuno-electron microscopy. Meth. Molec. Biol., vol. 161 Cytoskeleton Methods and Protocols, ed. R.H. Gavin, Humana Press Inc., Totowa, NJ, 133-139Google Scholar