Protocols for a Rapid Clean-up/Extraction Procedure and an Improved P45ORGS Dioxin Screening Assay for Sediments

摘要

The purpose of this technical note is to describe protocols for performance of an improved biomarker-based screening assay for dioxin toxic equivalents (TCDD TEQs) in sediments and other environmental samples using a recombinant human hepatoma cell line. For background refer to McFarland, McCant, and Inouye (1998) in which the use of cultured mammalian cells as the basis of assays for dioxins in environmental samples is described. There are several reasons why using cultured animal cells in assays for these contaminants is attractive. First, cell-based assays cost far less to perform and are done far more quickly than, for example, gas chromatograph/mass spectrometer (GC/MS) analysis of dioxins; the difference in cost is at least an order of magnitude, and may be more depending on the number of samples done in a batch, the number of replicates of each sample, and other factors. Additionally, the sensitivity of the cell-based assays can be made to be of the same order as that of the GC/ MS. For these reasons, the cells can provide screening tests of sediment samples that permit the prioritization of sites to receive definitive chemical analysis when analyses are required for regulatory or other purposes. When cleanup and remediation involving soils or sediments contaminated with polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), or polychlorinated dibenzodioxins/furans (PCDDs/PCDFs) are issues, the cells offer a less expensive alternative to chemistry for monitoring the effectiveness of treatments. Since the costs are relatively much lower, many more samples can be assayed for the same resource expenditure, allowing better characterization of the extent of contamination at sites.