NanoPhotometer
®
NP80/N60/N50/C40
User Guide Version 3.1
49
With background and with dye correction:
C =
�(
A
260
−
A
BKG
) −
�
cf
dye
*
�
A
max,dye
−
A
BKG
���
*
ε
nuc
*
Đ
With background and without dye correction:
C =
(
A
260
−
A
BKG
)
*
ε
nuc
*
Đ
Without background and with dye correction:
C =
�
A
260
−
cf
dye
* A
max,dye
�
*
ε
nuc
*
Đ
Without background and without dye correction:
C = A
260
*
ε
nuc
*
Đ
C
Concentration in ng/µl
A
260
Absorbance at 260 nm (10 mm path)
A
BKG
Absorbance at selected background wavelength (10 mm path)
A
max,dye
Absorbance value at the absorbance maximum of the dye (10 mm path)
ε
nuc
Extinction coefficient/nucleic acid factor in ng*cm/µl
cf
dye
Dye-dependent correction factor at 260 nm
Đ
Manual dilution factor
Note:
Dye correction is only available for single dye selection.
Dye Concentration
For dye-labeled nucleic acids, the concentration of the dye is calculated using a modified form
of the Beer-Lambert equation. For these calculations, the instrument considers the absorption
maximum of the dye, the dye-specific extinction coefficient (see Table 2). The dye concentration
is calculated with or without background correction as follows:
With background correction:
C =
�
A
max,dye
− A
BKG
�
* Ð
ε
dye
* 10
6
Without background correction:
C =
A
max,dye
*
Đ
ε
dye
* 10
6
C
Concentration in ng/µl
A
max,dye
Absorbance value at the absorbance maximum of the dye (10 mm path)
A
BKG
Absorbance at 320 nm (10 mm path)
