NICD final results for the Q-Preven ..January 2012

1. OFFICE OF THE DEPUTY DIRECTOR
VIROLOGY
NATIONAL INSTITUTE FOR COMMUNICABLE DISEASES
1 Modderfontein Road, Sandringham, 2031
Tel: +27 (0)11 386-6328 Fax: +27 (0)11 386-6411
Validation of the Q – Preven HIV 1 + 2 DBS Immunoenzyme Kit
Summary:
The Q-Preven HIV 1+2 DBS kit is an enzyme immunosorbent assay (ELISA) for the detection of
antibodies against HIV 1, HIV 2 and HIV 1 subtype O in Dried Blood Spot Specimens (DBS). The
kit consists of the following items: Dried Blood Spot Collection Kit which consists of the filter paper
and lancet; and the Test Kit which consists of ELISA Microplate and ELISA reagents required to
conduct an ELISA test. Supplies with the kit are negative and positive dried blood spot controls.
The following steps were completed during the validation:
Replicate testing using Kit Controls:
The negative DBS control and the positive DBS control from the Q-Preven test kit was tested 8
times in the same run and the results analyzed. All the controls passed validation and all controls
run as samples were within acceptable ranges i.e. the negative controls were negative and the
positive controls were positive.
Precision and Accuracy Testing:
Three negative and three positive controls taken from the Q-Preven test kit were tested over a
period of five consecutive days. The same operator tested the controls over the five day period and
the same plate washer, plate incubator and plate reader was used during the testing. The results of
the precision and accuracy testing are listed in Table 1 below:

2. Table 1
ID Day 1 - Day 2 - Day 3 - Day 4 - Day 5 - MEAN SD %CV
Ratio Ratio Ratio Ratio Ratio
Negative 0.317 0.332 0.347 0.450 0.365 0.3622 0.0522 14.41%
control
Negative 0.328 0.328 0.325 0.399 0.355 0.347 0.0315 9.08%
control
Negative 0.257 0.328 0.332 0.383 0.329 0.3258 0.0449 13.78%
control
Positive 16.845 22.969 21.487 15.192 16.589 16.6164 3.3971 18.25%
control
Positive 18.506 22.969 17.776 19.038 19.579 19.5736 2.0116 10.28%
control
Positive 19.642 22.969 19.949 19.038 19.579 20.2354 1.563 7.72%
control
The %CV is detailed in the kit insert as follows for Inter Assay Reproducibility:
Negative 7.3%
Positive 3.5%
The %CV is detailed in the kit insert as follows for Inter Assay Repetitively:
Negative 17.3%
Positive 9.5%

3. The %CV obtained for all the negative samples should be between 7.3% and 17.3%. All three
negative control %CV was less than 17.3% and is acceptable. The OD value between each
negative sample over the 5 days was <30%, therefore Accuracy between each negative control
reading was good.
The %CV obtained for all the positive samples should be between 3.5% and 9.5%. Two of the three
positive control %CV was out of the acceptable range. The OD value between each positive sample
over the 5 days was <30%, therefore Accuracy between each positive control reading was good.
Sensitivity and Specificity testing:
50 known negative DBS samples and 42 known positive DBS samples were randomly selected and
tested on the Q-Preven assay. The result of the samples on the Q-Preven assay is 100% in
concordance with the initial NICD laboratory results. The sensitivity and specificity of the Q-Preven
Assay is listed below.
Sensitivity: 100%
Specificity: 100%
Negative Predictive Value: 100%
Positive Predictive Value: 100%
Replicate Testing - New Controls
Additional controls were tested.The lot numbers received were 2028200180 and 2028300180 for the
negative and the positive controls respectively. The negative and the positive controls were run 8
times in the same run and the results analyzed. All controls passed validation and all the controls
run as samples were within acceptable ranges i.e. the negative controls were negative and the
positive controls were positive.

4. The test method, calculation procedure, specifications of Validity and Interpretation of results was
taken from the Q-Preven Package insert Revision 3 – 28/12/2011
Limitations of Validation:
Specimens known to be positive or negative based on NICD test results were used.
There was no direct comparison testing between plasma/serum and dried blood spot testing to
assess performance of the kit.
Limited numbers of specimens were used for sensitivity and specificity to demonstrate that the
assay performed as expected.
General comment
The package insert although readable requires additional editing to ensure that there is no ambiguity
in terms of performing the assay.
Testing and Excel Spreadsheets done by: Ushmita Patel
Date: 28 December 2011
Report compiled by: Beverley Singh and Ushmita Patel
Date: 11 January 2012
Report Reviewed and Approved By: Prof Adrian J Puren
Date: 11 January 2012
Signature:
The report is not an endorsement or otherwise of the product.