Two trials of external quality assessment were performed in 2003. Thirteen test items of immunoassay with ten control materials were surveyed. The response rate of external quality assessment for Immunoassay Subcommittee were 93.8% and 92.8%. Ten control materials were consisted of 8 home-made pooled sera and 2 commercial control sera. The results are summarized as follows. 1. Laboratories participating in external quality control program of immunoassay were 259 laboratories and the response rate were 93.8% and 92.8% in 2003. 2. Chemiluminiscence immunoassay autoanalyzer was now widely introduced comparing to previous years and now it is the most popular analyzer in the field of immunoassay testing. 3. Still some test items show big variations of the test results of the same control material according to autoanalyzer. Generally the quality of the participating laboratories seems to be thought being improved. And in the following years, new planning of the statistic analysis and some standardization protocols could be introduced.
Immunoassay* ; Korea* ; Quality Control

No abstract available.
Cytomegalovirus* ; Humans* ; Immunoassay*

Two trials of external quality assessment were performed in 2004 as previous year. Thirteen test items of immunoassay with ten control materials were surveyed. The response rate of external quality assessment for Immunoassay Subcommittee were 94.4% and 98.6%. Ten control materials were consisted of 8 home-made pooled sera and 2 commercial control sera (LyphoCheck, BioRad, USA). The results are summarized as follows. 1. Laboratories participating in external quality control program of immunoassay were 259 laboratories and the response rate were 94.4% and 98.6% in 2004. 2. Chemiluminiscence immunoassay autoanalyzers were most widely used in the field of immunoassay testing. 3. A new test item CA125 was introduced in this year from the second trial of external quality survey. 4. Still some test items show big variations of the test results of the same control material according to autoanalyzers. The quality of the participating laboratories seems to be thought being continuously improved. And, some new methods of the statistic analysis and some standardization protocols were considered to be introduced in the surveillance systems.
Immunoassay* ; Quality Control

Two trials of external quality assessment were performed in 2002. Thirteen test items of immunoassay with eight control materials were surveyed. The response rate of external quality assessment for Immunoassay Subcommitee were 94.3% and 94.5% in each trial. Eight control materials were consisted of 6 home-made pooled sera and 2 commercial control sera. The results are summarized as follows. 1. Laboratories participating in external quality control program of immunoassay were 233 to 241 laboratories and the response rate were 94.3% and 94.5% in 2002. 2. Chemiluminiscence immunoassay autoanalyzer was widely introduced comparing to previous years and now it is the most popular analyzer in the field of immunoassay testing. 3. Still some test items show wide variations of the test results of the same control material. But, generally the quality of the participating laboratories seems to be thought being improved.
Immunoassay* ; Korea* ; Quality Control

Antigens ; Immunoassay ; methods

BACKGROUND: Hemoglobin A1c (HbA1c) is widely used for the diagnosis of diabetes and monitoring of glycemic control. Recently, there is an increasing demands of HbA1c as an emergency outpatient test. We performed this study to evaluate the clinical utility of Dimension HbA1c immunoassay (Dade Behring, Newark, DE, USA). METHODS: Dimension HbA1c was evaluated for linearity, precision, method comparison, and speed. It was compared with VARIANT II Turbo (Bio-Rad Laboratories, Hercules, CA, USA). RESULTS: Dimension HbA1c showed within-run and total imprecision (CVs) of less than 2.0% and 2.5%, respectively. It revealed a good linearity to about 20%. Comparison studies between Dimension HbA1c and VARIANT II Turbo yielded a good correlation (r=0.990). The elapsed time for analysis was 7.5 min for the first specimen and 0.5 min for the succeeding ones. CONCLUSIONS: Dimension HbA1c provides acceptable performances and is suitable for the the emergency outpatient test.
Emergencies ; Hemoglobins ; Humans ; Immunoassay ; Outpatients

Lot-to-lot reproducibility is an important issue in immunoassays and reagent lot-to-lot comparability test comparing the results of new reagent lot with those of used lot using patients' samples or controls is usually performed to detect the difference between lots. However, there are no universally used acceptability criteria regarding reagent lot-to-lot comparability test. We performed reagent comparability test between different lots of alpha-fetoprotein (AFP) reagents and tried to determine its comparability by several criteria. Both the commercialized controls and in-house controls for AFP made from pooled patients' sera were measured 10 times using the old and new lots of reagents, whenever a reagent lot was changed. The differences in the mean control values, the percent difference (% difference), and the difference to between-run standard deviation ratio (D:SD ratio) between successive lots were calculated. We compared the results of reagent comparability test to arbitrarily determined acceptability criteria suggested by CLSI C54-A. Although comparability between reagent lots was determined according to how strictly we set the criteria, some lot-to-lot differences between certain pairs of lots exceeded the criteria. We hope that the results of this study might be helpful to perform reagent lot-to-lot comparability test and set the criteria for reagent comparability test between lots in other laboratories.
alpha-Fetoproteins ; Immunoassay ; Indicators and Reagents

BACKGROUND: We evaluated three commercially available vitamin D assays to evaluate and compare the correlation and accuracy among them. METHODS: Vitamin D was measured in 71 patient samples using the Architect 25-OH vitamin D assay (Abbott), the ADVIA Centaur vitamin D total assay (Siemens), and the LIAISON 25 OH vitamin D total assay (Diasorin). The evaluation made use of both patient samples and standard reference material, SRM 972. To analyze correlations and differences, Pearson's correlation coefficients and paired sample t-tests were performed. RESULTS: Correlations among the three evaluated assays showed strong positive linear relationships (correlations among Siemens and DiaSorin, DiaSorin and Abbott, Abbott and Siemens: r=0.935, r=0.927, r=0.909, respectively). Mean (SD) vitamin D values on Siemens, Abbott, and DiaSorin assays in the 71 patient samples were 23.09 (10.41), 16.75 (11.26), and 16.76 (9.32), respectively. Results for the Siemens assay were significantly different from the other two methods (P<0.001). Target values for SRM 972 level 1, 2, 3, and 4 were 23.9, 14.0, 44.9, and 35.4, respectively. The Abbott, Siemens, and Diasorin assay values were closest to the target values in level 1, levels 2 and 3, and level 4, respectively. CONCLUSIONS: Correlations among vitamin D assays were good; however, the mean values of the Siemens assay were significantly higher than those of DiaSorin or Abbott. We found significant differences in vitamin D levels and discrepancies between patient samples and SRM 972 samples, which should be considered during use in a clinical setting.
Humans ; Immunoassay ; Vitamin D* ; Vitamins*

A fluorescence polarization immunoassay (FPIA) was developed for the analysis ofaflatoxins (AFs) using an anti-aflatoxin B1 (AFB1) monoclonal antibody and a novel fluorescein-labeled AFB1 tracer. The FPIA showed an IC50 value of 23.33 ng/mL with a limit of detection of 13.12 ng/mL for AFB1. The cross-reactivities of AFB1, AFB2, AFG1, AFG2, AFM1, and AFM2 with the antibody were 100%, 65.7%, 143%, 23.5%, 111.4%, and 2%, respectively. The group-specificity of anti-AFB1mAb indicated that the FPIA could potentially be used in a screening method for the detection of total AFs, albeit not AFG2 and AFM2. The total time required for analyzing 96 samples in one microplate was less than 5 min. This study demonstrates the potential usefulness of the FPIA as a rapid and simple technique for monitoring AFs.
Aflatoxins ; analysis ; Fluorescence Polarization Immunoassay

No abstract available.
Immunoassay ; Prostate ; Prostate-Specific Antigen