Cannabinoids II

Catalog Number: 04491009190

SYSTEM INFORMATION

For cobas c 311/501 analyzers:

INTENDED USE

Cannabinoids II (THC2) is an in vitro diagnostic test for the qualitative and semiquantitative detection of cannabinoids in human urine on Roche/Hitachi cobas c systems at cutoff concentrations of 20 ng/mL, 50 ng/mL and 100 ng/mL. Semiquantitative test results may be obtained that permit laboratories to assess assay performance as part of a quality control program. Semiquantitative assays are intended to determine an appropriate dilution of the specimen for confirmation by a confirmatory method such as gas chromatography/mass spectrometry (GC‑MS).

STORAGE AND STABILITY

 Shelf life at 2‑8 °C: See expiration date on cobas c pack label
On‑board in use and refrigerated on the analyzer: 8 weeks
Do not freeze.

Specimen collection and preparation

CALIBRATION

 a) See Result section.

 Calibrators Semiquantitative applications
20 ng/mL cutoff assay
S1‑5: Preciset DAT Plus II calibrators, CAL 1‑50, 10, 20, 40, 100 ng/mL
50 ng/mL cutoff assay
S1‑5: Preciset DAT Plus I calibrators, CAL 1‑4, 60, 20, 50, 100, 300 ng/mL
100 ng/mL cutoff assay
S1‑5: Preciset DAT Plus I calibrators, CAL 1, 3‑60, 50, 100, 200, 300 ng/mL
Qualitative applications
20 ng/mL cutoff assay
S1: Preciset DAT Plus II calibrator - CAL 320 ng/mL
50 ng/mL cutoff assay
S1: C.f.a.s. DAT Qualitative Plus, C.f.a.s. DAT Qualitative Plus Clinical, or Preciset DAT Plus I calibrator - CAL 350 ng/mL
100 ng/mL cutoff assay
S1: Preciset DAT Plus I calibrator - CAL 4100 ng/mL
The drug concentrations of the calibrators have been verified by GC‑MS.
Calibration K Factor For the qualitative applications, enter the K Factor as -1000 into the Calibration menu, Status screen, Calibration Result window.
Calibration mode Semiquantitative applications
Result Calculation Mode (RCM)a
Qualitative applications
Linear
Calibration frequency Full (semiquantitative) or blank (qualitative) calibration• after reagent lot change• as required following quality control procedures

CALIBRATION K FACTOR

FOR THE QUALITATIVE APPLICATIONS, ENTER THE K FACTOR AS -1000 INTO THE CALIBRATION MENU, STATUS SCREEN, CALIBRATION RESULT WINDOW.

CALIBRATION MODE

CALIBRATION FREQUENCY

FULL (SEMIQUANTITATIVE) OR BLANK (QUALITATIVE) CALIBRATION• AFTER REAGENT LOT CHANGE• AS REQUIRED FOLLOWING QUALITY CONTROL PROCEDURES

CALIBRATION INTERVAL MAY BE EXTENDED BASED ON ACCEPTABLE VERIFICATION OF CALIBRATION BY THE LABORATORY.

FOR THE SEMIQUANTITATIVE ASSAY, THE ANALYZER COMPUTER CONSTRUCTS A CALIBRATION CURVE FROM ABSORBANCE MEASUREMENTS OF THE STANDARDS USING A 4 PARAMETER LOGIT‑LOG FITTING FUNCTION (RCM). THE LOGIT‑LOG FUNCTION FITS A SMOOTH LINE THROUGH THE DATA POINTS. THE ANALYZER COMPUTER USES ABSORBANCE MEASUREMENTS OF SAMPLES TO CALCULATE DRUG OR DRUG METABOLITE CONCENTRATION BY INTERPOLATION OF THE LOGIT‑LOG FITTING FUNCTION.

SEE THE "SPECIFIC PERFORMANCE DATA" SECTION OF THIS DOCUMENT FOR INFORMATION ON SUBSTANCES TESTED WITH THIS ASSAY. THERE IS THE POSSIBILITY THAT OTHER SUBSTANCES AND/OR FACTORS MAY INTERFERE WITH THE TEST AND CAUSE ERRONEOUS RESULTS (E.G., TECHNICAL OR PROCEDURAL ERRORS).

Representative performance data on a Roche/Hitachi analyzer are given below. Results obtained in individual laboratories may differ.

RESULTS OF THIS ASSAY YIELD ONLY APPROXIMATE CUMULATIVE CONCENTRATIONS OF THE DRUG AND ITS METABOLITES (SEE "ANALYTICAL SPECIFICITY" SECTION).

The specificity of this assay for various cannabinoids and cannabinoid metabolites was determined by generating inhibition curves for each of the compounds listed and determining the approximate quantity of each compound that is equivalent in assay reactivity to the 20 ng/mL, 50 ng/mL and 100 ng/mL Δ9 COOH‑THC assay cutoff. The following results were obtained on a Roche/Hitachi 917 analyzer.

SPECIFIC PERFORMANCE DATA

Representative performance data on a Roche/Hitachi analyzer are given below. Results obtained in individual laboratories may differ.

PRECISION

Precision was determined in an internal protocol by running a series of calibrator and controls (repeatability n = 20, intermediate precision n = 100). The following results were obtained on a Roche/Hitachi cobas c 501 analyzer.

PRECISION WAS DETERMINED IN AN INTERNAL PROTOCOL BY RUNNING A SERIES OF CALIBRATOR AND CONTROLS (REPEATABILITY N = 20, INTERMEDIATE PRECISION N = 100). THE FOLLOWING RESULTS WERE OBTAINED ON A ROCHE/HITACHI 501 ANALYZER.

INTERMEDIATE PRECISION

INTERMEDIATE PRECISION

INTERMEDIATE PRECISION

ANALYTICAL SPECIFICITY

The specificity of this assay for various cannabinoids and cannabinoid metabolites was determined by generating inhibition curves for each of the compounds listed and determining the approximate quantity of each compound that is equivalent in assay reactivity to the 20 ng/mL, 50 ng/mL and 100 ng/mL Δ9 COOH‑THC assay cutoff. The following results were obtained on a Roche/Hitachi 917 analyzer.

ARMBRUSTER DA, SCHWARZHOFF RH, PIERCE BL, ET AL. METHOD COMPARISON OF EMIT II AND ONLINE WITH RIA FOR DRUG SCREENING. J FORENSIC SCI 1993;38:1326-1341.