So proteins of similar molecular weight
can have quite different absorbances, since they can have completely different Tryptophan and
Tyrosine content. UV absorbance of aromatic side chains is also affected by protein structure.
Therefore conditions which affect structure, such as temperature, pH, ionic strength, or the
presence of detergents, can affect the ability of aromatic residues to absorb light at 280 nm,
and change the value of the protein’s extinction coefficien