Derivation of Scatter Correction

(our regards to Dr. Sriram Krishnaswamy for his helpful comments)

A_{280 = A°280 + Isc,280}

Where: A280 = observed absorbance

A°280 = actual instrinsic absorbance of the protein

Isc, 280 = absorbance due to scatter or dispersion

A280 = A°280 + Isc,280

A°280 = A280 – Isc,280

Isc,280 is proportional to 1/

λ^{4 and equal to K (1/λ4) = K (1/(280)4}

where K = proportionality constant

Likewise,

A320 = A°320 + Isc,320

For proteins, A°320 = 0. (not valid for proteins absorbing at 320 nm or for proteins larger than λ (e.g. von Willebrand factor).

Therefore:

A320 = Isc,320 = K(1/(320)4)

K = A320 x (320)4 = Isc,280 x (280)4

Isc,280 = A320 ((320)4/(2804) = 1.7 x A320

And

A°280 = A280 – 1.7(A320)