Question

why do we select wavelength of 280nm during selective precipitation of egg albumin ?

Answer 1

Egg albumin contains Proteins that can absorb ultraviolet light with wavelengths in the range of 210nm to 280 nm .
In proteins, various aromatic amino acid are present which absorb UV light at different wavelengths. Peptide bonds absorb photons at 210 nm, while aromatic residues such as Tryptophan and Tyrosine will absorb light at 280 nm. Phenylalanine will also absorb at photons at the 260 nm wavelength.

The UV light at 280 nm is widely used due to its simplicity, ease of use, and decreased chemical absorption compared to other wavelengths in Precipitation of egg albumin.