Thermo Scientific NanoDrop Lite Plus User Manual page 15

Thermo Scientific
Protein concentration is calculated using the Beer-Lambert equation:
c = A/e*b
where,
c = the protein concentration
A = the sample absorbance
e = the protein specific mass extinction coefficient
b = the pathlength in cm
The protein specific concentration measurement options are:
1 Abs= 1 mg/mL: Recommended when extinction coefficient is unknown and
rough estimate of protein concentration is acceptable for a solution with no other
interfering substances. Assumes 0.1% (1 mg/mL) protein solution produces 1.0A at
280 nm (where pathlength is 10 mm), i.e., E1% = 10.
IgG: Suitable for most mammalian antibodies (i.e., immunoglobulin G or IgG).
Calculates protein concentration using mass extinction coefficient (E) of
13.7 L/gm-cm at 280 nm for 1% (i.e., 10 mg/mL) IgG solution. Assuming MW is
150,000 Da, molar extinction coefficient at 280 nm for IgG is approximately
-1 -1
210,000 M cm .
BSA: Calculates BSA (Bovine Serum Albumin) protein concentration using mass
extinction coefficient (E) of 6.7 L/gm-cm at 280 nm for 1% (i.e., 10 mg/mL) BSA
solution. Assuming MW is 66,400 daltons (Da), molar extinction coefficient at
280 nm for BSA is approximately 43,824 M
Lysozyme: Calculates lysozyme protein concentration using mass extinction
coefficient (E) of 26.4 L/gm-cm at 280 nm for 1% (i.e., 10 mg/mL) lysozyme solution.
Assumes molar extinction coefficient for egg white lysozyme ranges between 36,000
-1 -1
M cm and 39,000 M-1cm
Other protein (E &MW): User entered molar extinction coefficient and molecular
weight. Assumes protein has known molar extinction coefficient (E) and molecular
weight (MW), where:
(E )*10=(E
molar percent
Enter MW in kiloDaltons (kDa) and molar extinction coefficient (E) in M
by 1000 (i.e., E/1000). For example: For protein with molar extinction coefficient of
-1 -1
210,000 M cm , enter 210.
Other Protein (E 1%): User entered mass extinction coefficient. Assumes protein
has known mass extinction coefficient (E). Enter mass extinction coefficient in
L/gm-cm for 10 mg/mL (E1%) protein solution.
-1
cm
-1
.
)*(MW )
protein
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NanoDrop Lite Plus User Guide
Protein Measurements
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NanoDrop Lite Plus User Guide
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