Absorbance measures the ability of the substance to absorb light at a specific wavelength.
Absorbance is also equal to the product of molar absorptivity, path length and molar concentration.
The mathematical expression is given as:
(1)
where, A = absorbance
= molar absorptivity
l = path length
c = molar concentration.
The above formula is said to Beer's Law.
Absorptivity of protein x =
Path length = 1 cm
Molar concentration =
Put the values in formula (1)
=
Thus, absorbance at 280 nm =