Sample Collection Tubes Research Articles

Liquid-chromatographic monitoring of cytosine arabinoside and its metabolite, uracil arabinoside, in serum.

This is a "high-performance" liquid-chromatographic method for quantifying the antileukemic drug cytosine arabinoside (cytarabine; 1-beta-D-arabinofuranosylcytosine; Ara-C), with a structural analog, 5-methylcytidine, as the internal standard. We used a C18 reversed-phase column and ammonium acetate (0.5 mol/L, pH 6.5) as the mobile phase, monitoring the column effluent at 280 nm. Tetrahydrouridine was present in the sample-collection tubes to inhibit conversion of cytosine arabinoside to uracil arabinoside. The standard curve is linear to 100 mg/L. Analytical recovery is 98%. Coefficients of variation for within-run and between-run imprecision were 2.0% and 4.3% at 20 mg/L and 2.7% and 2.7% at 80 mg/L, respectively. Assay sensitivity was limited by the amount of endogenous material in each patient's serum, making assay of a pre-infusion sample necessary for accurate calculations. In a trial patient population, the assay was shown to have potential for the detection of toxic concentrations in patients receiving high doses of Ara-C.

Verification of Intoximeter 3000 breath alcohol concentration by magnesium perchlorate tube method in long-term field program.

The anhydrous magnesium perchlorate (MPT) breath alcohol sample collection tube was analyzed by gas chromatography (GC) to verify paired breath alcohol concentrations obtained from 18 Intoximeter 3000 (IR) instruments under normal conditions of use. This study compares the accuracy, precision, and reliability of actual driving-while-intoxicated (DWI) IR breath alcohol evidence gathered by field law enforcement personnel with the GC results of the MPT alcohol analysis. The IR and MPT-GC breath alcohol concentration results from a total of 1024 individuals were determined. Results of 530 (51.7%) MPT-GC breath alcohol analyses deviated within +/- 0.010 g/210 L from their paired IR breath alcohol result; 817 (79.7%) and 945 (92.3%) MPT-GC breath alcohol analyses deviated within +/- 0.020 and +/- 0.030 g/210 L, respectively. Confidence interval limits at various probability levels are tabulated and show expected reliability of a single predicted IR breath alcohol concentration from the IR on MPT-GC linear regression analysis.

A quantitative automated immunoassay for fibrinogen/fibrin degradation products.

We describe a prototype quantitative automated assay for fibrin and fibrinogen degradation products, a particle-enhanced turbidimetric inhibition immunoassay (PETINIA) in the Du Pont aca discrete clinical analyzer. This assay involves a latex particle reagent with covalently bound fibrinogen and a polyclonal antiserum raised in rabbits against human fibrinogen. A special secondary sample-collection tube quantitatively removes fibrinogen from citrated plasma and inhibits further fibrinolysis, independent of heparin concentration. The assay range is 0-100 mg/L, in fibrinogen equivalents. The CV for the assay is less than 10% when performed with the aca. Nonclottable fibrin and fibrinogen fragments are measured by the assay, the greatest sensitivity being directed at the E domain of the fibrinogen molecule. We illustrate with case studies the potential of this assay for providing clinical information not obtainable with currently available qualitative and semi-quantitative assays.