7. Quality Control
96
Instructions for Use for INFINITE M1000 PRO No. 30064852 Rev. No. 1.0
2011-09
7.2 Definitions
7.2.1
Detection Limit (LOD)
The detection limit is defined as the concentration of the fluorophore at which the
corresponding signal can be distinguished from the background within a certain
statistical probability. The LOD is calculated according to the following formula:
B
Stdev
*
3
*
B)
(F
C
LOD
−
=
C: Concentration of the fluorophore (concentration is at least 100 times higher
than the LOD).
Stdev
B
: standard deviation of the blank.
F: Measured RFU value of the fluorophore.
B: Measured RFU value of the blank.
7.2.2 Uniformity
Uniformity is a measure for the well-to-well variations when measuring a multi-
well-plate. The uniformity is either calculated as a percentage deviation from the
mean value or (for low OD values) as a maximal deviation in mOD.
7.2.3 Linearity
Linearity is defined as the relationship between the concentration of
fluorophore/dye and the corresponding signal probability. To evaluate linearity, a
dilution series of the appropriate dye is measured and the r-square value is
assessed according to the following formula:
SST
SSR
r
=
2
SST
SSR
r
=
2
SSR: Sum of squares of the regression.
SST: Total sum of squares.
(
)
∑
=
−
=
n
i
i
i
y
y
SSR
1
2
ˆ
ω
)
2
1
(
∑
=
−
=
n
i
i
i
y
y
SST
ω
7.2.4 Accuracy
Accuracy is the ability of a measuring instrument to give responses close to a true
value. The accuracy is either calculated as percentage deviation from the true
value or for low OD values as the deviation from the true value in mOD.
