Abraxis: 522015: Microcystins in water by Immunoassay, Direct Monoclonal Microtiter Plate
|
Official Method Name
|
Abraxis Microcystin-DM ELISA Plate Kit PN 522015 |
|---|---|
|
Current Revision
| 2007 |
|
Media
|
WATER |
|
Instrumentation
|
Immunoassay |
|
Method Subcategory
|
Organic |
|
Method Source
|
|
|
Citation
|
|
|
Brief Method Summary
|
Microcystins are detected using a colorimetric immunoassay (ELISA) procedure. A sample (0.10 mL), enzyme conjugate (Microcystins-HRP), and an antibody solution against Microcystins are added to plate wells pre-coated with monoclonal antibodies (goat anti-mouse). Both the Microcystins (if present) in the sample and Microcystins-HRP conjugate compete to bind to the antibody solution in proportion to their concentrations. The anti-Microcystins antibodies are then bound to the immobilized monoclonal antibodies on the plate. After an incubation, the unbound molecules are washed and decanted. A substrate is then added which is catalyzed by the enzyme and converted from a colorless to a blue solution. The reaction is terminated with the addition of a dilute acid. The concentration of Microcystins in the sample is determined by measuring its absorbance at a specific wavelength (450nm) using a photometer and comparing its absorbance to the absorbance of the calibrators. |
|
Scope and Application
|
This method determines Microcystins and Nodularins in water (groundwater, surface water, well water). |
|
Applicable Concentration Range
|
0.10 - 5.0 |
|
Interferences
|
Cross-reactivity: Microcystins (YR, RR, LA) and Nodularins, and high concentrations of N-hemi-ADDA and ADDA may produce false positive responses for Microcystin-LR. |
|
Quality Control Requirements
|
(A) Calibration with 5 standards and 1 blank, all analyzed in duplicate. (B) Precision: 3 matrix samples with different levels in the range for quantitative analysis analyzed daily for 5 days with 5 replicates in each of 5 assays. (C) Accuracy: 5 matrix samples spiked with the target analyte at 4 different levels in the range for quantitative analysis. (D) Validation: Analysis of 4 positive and 4 negative samples by an independent method, for confirmation. |
|
Sample Handling
|
Samples are collected in glass containers with Teflon-lined caps; for compliance monitoring, samples should be held no longer than 14 days. If samples are held frozen, they can be held for longer periods of time. Immunoassay reagents are stored refrigerated until use. Samples containing gross particulate matter should be filtered using a 1 micron filter or centrifuged before use. Drinking water samples are typically dechlorinated with 0.008% sodium thiosulfate. |
|
Maximum Holding Time
|
14 days at 4 C, longer if frozen |
|
Relative Cost
|
Less than $50 |
|
Sample Preparation Methods
|
