NanoPhotometer
®
NP80/N60/N50/C40
User Guide Version 3.1
57
Note:
The illumination of the sample window can be switched off in the
preferences.
11. Use a lint-free laboratory wipe to clean both the sample window and
mirror prior to applying the next sample.
Note:
It can be helpful to apply the blank a second time and read it as a
sample to ensure a proper blank.
12. Apply sample to the sample window and press the sample button to
initiate the measurement.
C
ALCULATIONS
Protein UV280 Concentration
The protein concentration in the Protein UV method is calculated with the absorbance value of
the sample at 280 nm along with the extinction coefficient defined by the user. The protein
concentration is calculated with or without background correction as follows:
With background correction:
C =
(
A
280
−
A
BKG
)
*
ε
prot
* Ð
Without background correction:
C = A
280
*
ε
prot
* Ð
C
Concentration (mg/ml)
A
280
Absorbance at 280 nm (10 mm path)
A
BKG
Absorbance at selected background wavelength (10 mm path)
ε
prot
Extinction coefficient/protein factor in g*cm/l
Ð
Dilution factor
