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LVL
Enzymatic Acetaminophen-SL Assay
For The Determination Of Toxicological Levels In Serum & Plasma
INTRODUCTION
Acetaminophen is used as an analgesic in many different formulations. While therapeutic doses rarely cause adverse side effects, the effect of long term treatment is unclear. Cases have been reported where chronic, excessive use of acetaminophen has led to hepatotoxicity and nephrotoxicity. In cases of acute over-dosage, acetaminophen can cause severe hepatic damage leading to hepatic failure, if untreated. The management of acetaminophen over-dosage requires early detection of the drug in the bloodstream. Toxicity is generally reported at concentrations above 20 mg/dL (1324 μmol/L). N-acetylcysteine has been used as an “antidote” in overdose cases, in conjunction with intensive care. Early detection and diagnosis of acetaminophen-induced hepatotoxicity is important since initiation of treatment within eight hours of ingestion, decreases the potential of hepatic injury and mortality.
Test Principle
The majority of methods for the measurement of acetaminophen are based on either chromatographic or spectrophotometric test procedures. Chromatographic methods are specific for the parent compound but are not ideally suited for STAT laboratories. Spectrophotometric methods are simpler and more rapid but do not always offer the desired specificity. The DCL Acetaminophen assay is an enzymatic method utilizing the enzyme Acyl-Aminohydrolase. In the reaction, the enzyme cleaves the amide bond of the acetaminophen molecule, leaving p-aminophenol and acetate. The p-aminophenol then reacts with 8-hydroxyquinoline, in the presence of manganese ions, to form the colored compound 5-(4-iminophenol)-8-quinolone. The resulting increase in absorbance at 615 nm is directly proportional to the acetaminophen concentration in the test sample.
Key Features & Benefits
Field-Proven Performance – One of the most widely used liquid stable, enzymatic acetaminophen assays, with a documented history of performance in the most demanding clinical laboratories worldwide.
Liquid Stable Format – Liquid stable technology eliminates the need for reagent reconstitution procedures, saving time, errors, labor and reagent waste.
Dependable Results – The assay demonstrates superior performance characteristics with regard to linearity, accuracy, precision and sensitivity.
Testing Flexibility – Test either serum or plasma samples using fully automated testing procedures – an extensive listing of instrument applications is readily available.
Minimal Sample Requirements – The assay requires as little as five (5) μL of sample, making it ideal for pediatric and geriatric testing.
Fast Turnaround Time – Generate accurate and reliable test results in only eight (8) minutes.
Convenient & All Inclusive Packaging Design Regardless of laboratory size or workload, a packaging format, including all necessary reagents and standard material, is available to fit your testing requirements.
Specific Performance Characteristics
· Reportable Range (NCCLS EP6-P) – The reportable range of the assay using automated procedures will depend on the sample to reagent ratio, as well as other factors. However, for the majority of automated procedures, the assay provides a reportable range of 0.3 – 38.0 mg/dL (20 – 2,500 μmol/L).
· Accuracy (NCCLS EP9-P) – The performance of this method (y) was compared with the performance of another commercially available method (x) on a Roche/Hitachi® 717. A total of fifty-seven (57) patient serum samples, with values ranging from 0.6 – 34 mg/dL (41 – 2,250 μmol/L) were tested. This study yielded a correlation coefficient of 0.9976, with a resulting linear regression equation of y = 1.01x – 0.38 mg/dL (25.2 μmol/L). In another study, the performance of this method using plasma samples (y) was compared to this method using serum samples (x) on a Bayer ADVIA® 1650. Twenty-five (25) serum and plasma specimens were run, with values ranging from 0.04 – 19.5 mg/dL (2.7 – 1,319 μmol/L). This study yielded a correlation coefficient of 0.9996, with a linear regression equation of y = 1.01x – 0.01 mg/dL (0.7 μmol/L).
· Precision (NCCLS EP5-T2) – Precision estimates for Intra-Run performance were obtained on two (2) separate levels of commercially available control materials with concentrations of 1.7 mg/dL (115 μmol/L) and 14.4 mg/dL (950 μmol/L), run a total of twenty (20) times. The resulting SD’s were 0.02 mg/dL (1.2 μmol/L) and 0.08 mg/dL (5.2 μmol/L) respectively, generating CV%’s of 1.0 and 0.6. Total precision performance estimates were obtained by assaying the same controls in forty (40) runs conducted over twenty (20) days. The resulting SD’s were 0.02 mg/dL (1.6 μmol/L) and 0.26 mg/dL (17.5 μmol/L) respectively, generating CV%’s of 1.4 and 1.8.
Ordering Information
Product
Catalogue Number
Packaging Configuration
Acetaminophen-SL 505-10 R1: 1 x 10 mL;
R2: 2 x 10 mL;
Std: 1 x 5 mL
Acetaminophen-SL 505-30
R1: 3 x 10 mL;
R2: 6 x 10 mL;
Std: 1 x 5 mL
Supporting Products
Acetaminophen Standard
505-29S 1 x 5 mL DC-Aceta/Sal Level I Control
SE-008 6 x 3 mL
DC-Aceta/Sal Level II Control
SE-010 6 x 3 mL
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