Abraxis: 540041: DDE/DDT by Immunoassay, Microtiter Plate
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Official Method Name
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Abraxis DDE/DDT Plate Assay Kit (96T) PN 540041 |
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Current Revision
| 2003 |
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Media
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WATER |
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Instrumentation
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Immunoassay |
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Method Subcategory
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Organic |
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Method Source
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Citation
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Brief Method Summary
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DDE/DDT are detected using a colorimetric immunoassay (ELISA) procedure. A sample (0.05 mL) and an antibody against DDE/DDT are added to a microtiter plate well pre-coated with DDE/DDT coating conjugate. Both the DDE/DDT (when present in a sample) and the DDE/DDT coating conjugate compete for the binding sites of the antibody. After a washing step, a second antibody-HRP labeled is added and incubated. After a washing step, a substrate is 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 DDE/DDT in the sample is determined by measuring its absorbance at a specific wavelength (450 nm) using a plate photometer and comparing its absorbance to the absorbance of the calibrators. |
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Scope and Application
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This method determines DDE/DDT in water (groundwater, surface water, well water). It is capable of detecting p,p'-DDE; p,p'-DDD; o,p'-DDD; p,p'-DDT; and, o,p'-DDE. |
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Applicable Concentration Range
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1.25 - 75.0 |
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Interferences
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Quality Control Requirements
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(A) Calibration with 6 standards and 1 blank, all analyzed in duplicate. (B) Precision: 3 matrix samples with different levels inthe range for quantitative analysis analyzed daily for 3 days with 5 replicates in each of 5 assays. (C) Accuracy: 5 matrix samples spiked with the target analyte at 3 different levels in the range for quantitative analysis. (D) Validation: Analysis of 4 positive and 4 negative samples by an independent method for confirmation. |
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Sample Handling
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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. |
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Maximum Holding Time
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14 days at 4oC, longer if held frozen |
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Relative Cost
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Less than $50 |
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Sample Preparation Methods
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