V4 080306

TEST ELISA PARA CHAGAS III 

REPRODUCIBILITY, SENSITIVITY AND SPECIFICITY

1.- Reproducibility for three different lots of Test ELISA para Chagas III.

For each lot, four assays were run in different days. In each assay five replicates for samples and controls were included. The results are shown below in terms of the coefficient of variability (CV), within run (Table I), run to run (Table II) and lot to lot (Table III).

The CV was calculated from the absorbance/cut off ratio (A/CO) for the samples and from the absorbance for the controls (the values for controls absorbances and samples Absorbance/cut off ratios are shown only on Table III).

Table I: within run reproducibility

Table II: run to run reproducibility

Table III: lot to lot reproducibility

The lot to lot and run to run absorbance variations represented by the positive controls results were not higher than 11% and do not affect the overall performance of the test, which is given by the variations of the A/CO ratios of the samples.

The samples average CV for lots 1741202, 0900603 and 11407032 was 4.5%, 5.3% and 3.6% within run, and 1.7%, 3.9% and 3.0% run to run, respectively. The average lot to lot CV for samples was 2.2% not exceeding 3%.

These values shows an excellent overall reproducibility for the product.

2.- Test ELISA para Chagas III: Sensitivity Studies with three different lots.

To evaluate Test ELISA para Chagas IIIsensitivity, confirmed positive samples were assayed with three different lots. Results are shown in the following table:

These data shows 100% Sensitivity for the three lots evaluated.

3.- Test ELISA para Chagas III Specificity.

1060 fresh plasma samples from a Blood Bank from Santiago were assayed with Test ELISA para Chagas III lot Nº 1741202.Of them, 1057 samples were negative and three of the samples were positives.

Those three positive samples were confirmed as positives, by other three commercial ELISA assays and Western Blot.

The study shows 100% specificity.

René Díaz R. Quality Control Manager