This test utilises synthetic and recombinant antigens representing envelope and
gag glycoproteins of HIV 1 and 2, immobilised on a membrane,
enclosed in a specially designed test-device. 2 ml of the saliva
sample is measured, using the pipette provided with the kit. The
sample is filtered through the filter funnel and flows through
the membrane as antibodies in the sample, if present, react with
the antigens immobilised onto the membrane. Next, a reagent
consisting of a specific binding partner conjugated to colloidal
gold (Reagent B) is applied which binds to human antibodies (IgG)
that are attached to the antigens on the membrane. Within a few
minutes, the results appear on the membrane. Excess conjugate
is removed by applying additional Reagent A (buffer solution).
Appearance of a control dot shows that the test is functioning as
designed. Two pink dots approximately 2 mm in diameter indicate
an HIV reactive or positive specimen.
Results were determined by noting the development of pink
dots (C – control and T – test) on the membrane (Fig. 2). The
presence of the ‘‘C’’ dot was a necessity to validate the proper
functioning of the test. Results without the control dot were
termed as indeterminate and were not included in the calculations.
If both ‘‘C’’ and ‘‘T’’ were present it was read as positive, if only ‘‘C’’
was present it was considered negative and if only ‘‘T’’ was present
the test was not considered valid. Equivocal results (when the T
dot was faint) were decided by taking the consensus opinion of
two other observers.
Later, the results were cross checked with the standard serum
tests, tabulated and subjected to statistical analysis