Immunoassay screen

A number of different testing kits based on immunoassay technology are available for rapid field determination of certain groups of compounds, such as benzene-toluene-ethylbenzene-xylene (EPA 4030) or polynuclear aromatic hydrocarbons (EPA 4035, Polycyclic Aromatic Hydrocarbons by Immunoassay). The immunoassay screening kits are self-contained portable field kits that include components for sample preparation, instrumentation to read assay results, and immunoassay reagents. 

Oxaprozin- False-positive urine immunoassay screening tests for benzodiazepines have been reported in patients taking oxaprozin. False-positive test results may be expected for several days following discontinuation of oxaprozin therapy. 

Baker, D.B., RJ. Bushway, S. Adams, and C. Macomber (1993). Immunoassay screens for alachlor in rural wells False positives and an alachlor soil metabolite. Environ. Sci. Technol., 27 562-564. 

Negrusz, A., et. al. Highly Sensitive Micro-Plate Enzyme Immunoassay Screening and NCI-GC-MS Confirmation of Flunitrazepam and Its Major Metabolite 7-Aminoflunitrazepam in Hair. Journal of Analytical Toxicology 23 (6) (1999) 429-435. 

Benzodiazepines may be identified and quantified in serum, generally by HPLC, but such quantitative information is not warranted in cases of benzodiazepine overdose because serum levels are not predictive of severity of intoxication. However, a urine or serum immunoassay screening test for benzodiazepines is valuable to aid in the evaluation of patients with an unlmown cause of CNS depression. 

Cone EJ, Presley L, Lehrer M, Seiter W, Smith M, Kardos KW, et al. Oral fluid testing for drugs of abuse positive prevalence rates by Intercept immunoassay screening and GC-MS-MS confirmation and suggested cutoff concentrations. J Anal Toxicol 2002 26 541-6. 

A. Specific levels. Assays exist for semm and urine analysis, but are not generally available. In seven fatal infant cases, blood levels averaged 0.38 mg/L (range 0.10-0.95). Despite its stmctural similarity to opioids, dextromethorphan is not likely to produce a false-positive urine opioid immunoassay screen. However, it may produce a false-positive result on methadone and phencyclidine immunoassays. Dextromethorphan is readily detected by comprehensive urine toxicology screening. 

Note Immunoassay screening covering amphetamines, cannabinoids, cocaine, and morphine is also performed. 

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