Catalog Number: 05480167190

SYSTEM INFORMATION

RF‑II: ACN 8017

INTENDED USE

In vitro test for the quantitative determination of Rheumatoid Factors (RF‑II) in human serum and plasma on Roche/Hitachi cobas c systems. Measurements may be used as an aid in the diagnosis of rheumatoid arthritis.

THE CLASSIC PROCEDURE FOR THE QUANTITATION OF RHEUMATOID FACTORS IS BY AGGLUTINATION WITH IGG‑SENSITIZED SHEEP ERYTHROCYTES OR LATEX PARTICLES. PARTICULAR PROBLEMS OF THESE SEMIQUANTITATIVE METHODS ARE THE POOR BETWEEN‑LABORATORY PRECISION AND REPRODUCIBILITY, TOGETHER WITH STANDARDIZATION DIFFICULTIES. FOR THESE REASONS, NEW ASSAY METHODS SUCH AS NEPHELOMETRY, TURBIDIMETRY, ENZYME‑IMMUNOASSAYS AND RADIOIMMUNOASSAYS HAVE BEEN DEVELOPED. THE ROCHE RF ASSAY IS BASED ON THE IMMUNOLOGICAL AGGLUTINATION PRINCIPLE WITH ENHANCEMENT OF THE REACTION BY LATEX.

Precision was determined using human samples and controls in an internal protocol with repeatability (n = 21) and intermediate precision (3 aliquots per run, 1 run per day, 21 days). The following results were obtained:

STORAGE AND STABILITY

RF‑II
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
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

APPLICATION FOR SERUM AND PLASMA

cobas c 701/702 test definition
Assay type	2‑Point End
Reaction time / Assay points	10 / 21‑29
Wavelength (sub/main)	800/570 nm
Reaction direction	Increase
Unit	IU/mL
Reagent pipetting		Diluent (H2O)
R1	90 µL	–
R3	30 µL	–
Sample volumes	Sample	Sample dilution
		Sample	Diluent (NaCl)
Normal	3 µL	–	–
Decreased	6 µL	15 µL	135 µL
Increased	6 µL	–	–

CALIBRATION

Calibration interval may be extended based on acceptable verification of calibration by the laboratory.

Calibrators	S1: H2OS2‑6: Preciset RF
Calibration mode	RCM
Calibration frequency	Full calibration• after 180 days during shelf life• after reagent lot change• as required following quality control procedures

CALIBRATION MODE

CALIBRATION FREQUENCY

FULL CALIBRATION• AFTER 180 DAYS DURING SHELF LIFE• AFTER REAGENT LOT CHANGE• AS REQUIRED FOLLOWING QUALITY CONTROL PROCEDURES

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

LIMITS AND RANGES

Measuring range

MEASURING RANGE

10‑130 IU/mL

LOWER LIMITS OF MEASUREMENT

Lower detection limit of the test

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 AN INTERNAL PROTOCOL WITH REPEATABILITY (N = 21) AND INTERMEDIATE PRECISION (3 ALIQUOTS PER RUN, 1 RUN PER DAY, 21 DAYS). THE FOLLOWING RESULTS WERE OBTAINED:

RESULTS FOR INTERMEDIATE PRECISION WERE OBTAINED ON THE MASTER SYSTEM 501 ANALYZER.

METHOD COMPARISON

RF values for human serum and plasma samples obtained on a 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.

Rheumatoid Factors II