Diesse Chorus - Screen Test

Manuale operativo CHORUS
98 Rev. 0 del 06/2012
In the opposite case, the percentage of Avidity is determined by index
I ( %Av ) = OD
urea
x 100 / OD
ref
The result is then determined by the following comparison results:
• if I (%Av) > 40% High level ( H)
• if 40 > I (%Av) > 30% Doubtful (D)
• if I (%Av) < 30 % Low level (L)
5.3.6.1 Quality control
The verification routine of the QC involves processing the QC of a test batch with the corresponding
strip in the standard mode, like any sample, and determining the optical densities
OD
QCurea
= OD3u – OD1u
OD
QCref
= OD3r – OD1u
and subsequently the percentage of Avidity
I ( %Av ) = OD
QCurea
x 100 / OD
QCref
For the Avidity tests two different QC are available: one at low concentration (Low Avidity QCL), and
one at high concentration (High Avidity QCH).
Once the I (%Av ) has been determined, the result is supplied on the basis of the following criteria
• if QC is High and I (%Av) > 40% OK
• if QC is High and I (%Av) < 40% KO
• if QC is Low and I (%Av) < 30% OK
• if QC is Low and I (%Av) > 30% KO
5.3.7 S CREEN T EST
The calibration routines arise from the qualitative test method routines that foresee the definition and
the storage of parameter OD
cal
.
As for the titration and the quality control, two cases are possible, depending on the test:
a) Calculation with direct index
b) Calculation with reverse index
5.3.7.1 Sample dosing with direct index
The sample dosing routine with direct index foresees that, after determining
OD
sample
,= OD3 – OD1
The index is calculated:
• I
sample
= OD
sample
/ OD
cal
• And the result is supplied as follows:
if I
sample
≥ 1,2 Positive
if I
samplemp
< 0,8 Negative
if 1,2 ≥ I
sample
≥ 0,8 Doubtful