Homocysteine Enzymatic Assay

Catalog Number: 06542921190

SYSTEM INFORMATION

HCYS: ACN 8778

INTENDED USE

In vitro test for the quantitative determination of total L-homocysteine in human serum and plasma on Roche/Hitachi cobas c systems. The assay can assist in the diagnosis of patients suspected of having hyperhomocysteinemia or homocystinuria.

STORAGE AND STABILITY

HCYS
Shelf life at 2 8 °C: See expiration date on cobas c pack label.
On board in use and refrigerated on the analyzer: 4 weeks
On board on the reagent manager: 1 hour
Diluent NaCl 9 %
Shelf life at 2 8 °C: See expiration date on cobas c pack label.
On board in use and refrigerated on the analyzer: 4 weeks
On board on the reagent manager: 24 hours

Do not freeze.

APPLICATION FOR SERUM AND PLASMA

cobas c 701/702 test definition
Assay type 2-Point End
Reaction time / Assay points 10 / 28-38
Wavelength (sub/main) 700/340 nm
Reaction direction Decrease
Units µmol/L
Reagent pipetting Diluent (H2O)
R1 176 µL
R2 28 µL
R3 20 µL

CALIBRATION

Traceability: This method has been standardized against NIST SRM 1955 reference material.

Calibrators S1-5: HCYS Calibrator Kit
Multiply the lot-specific HCYS Calibrator Kit calibrator value by the factors below to determine the standard concentrations for the 5-point calibration curve:
S1: 0.050 S4: 0.500
S2: 0.100 S5: 1.00
S3: 0.250
Calibration mode RCM
Calibration frequency Full calibration• every 7 days• after reagent lot change• as required following quality control procedures

MULTIPLY THE LOT-SPECIFIC HCYS CALIBRATOR KIT CALIBRATOR VALUE BY THE FACTORS BELOW TO DETERMINE THE STANDARD CONCENTRATIONS FOR THE 5-POINT CALIBRATION CURVE:

CALIBRATION MODE

CALIBRATION FREQUENCY

FULL CALIBRATION

LIMITS AND RANGES

Measuring range

MEASURING RANGE

3-50 µmol/L

LOWER LIMITS OF MEASUREMENT

Limit of Blank and Limit of Detection

SPECIFIC PERFORMANCE DATA

Representative performance data on the analyzers are given below. Results obtained in individual laboratories may differ.

PRECISION

Precision was determined using human samples and controls in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP5 requirements with repeatability (n = 21) and intermediate precision (2 aliquots per run, 2 runs per day, 21 days). The following results were obtained:

PRECISION WAS DETERMINED USING HUMAN SAMPLES AND CONTROLS IN ACCORDANCE WITH THE CLSI (CLINICAL AND LABORATORY STANDARDS INSTITUTE) EP5 REQUIREMENTS WITH REPEATABILITY (N = 21) AND INTERMEDIATE PRECISION (2 ALIQUOTS PER RUN, 2 RUNS PER DAY, 21 DAYS). THE FOLLOWING RESULTS WERE OBTAINED:

INTERMEDIATE PRECISION

METHOD COMPARISON

Hcy values for human serum samples obtained on the Roche/Hitachi cobas c 701 analyzer (y) were compared with those determined using the corresponding reagent on a Roche/Hitachi cobas c 501 analyzer (x).

BABLOK W, PASSING H, BENDER R, ET AL. A GENERAL REGRESSION PROCEDURE FOR METHOD TRANSFORMATION. APPLICATION OF LINEAR REGRESSION PROCEDURES FOR METHOD COMPARISON STUDIES IN CLINICAL CHEMISTRY, PART III. J CLIN CHEM CLIN BIOCHEM 1988 NOV;26(11):783-790.