The starting value of the F350/F330 ratio can already contain valuable information. The starting value mainly depends on the amount of Trp residues and especially their position. Typical proteins range from 0.35 (most Trp residues buried) to 1.4 (most Trp residues solvent exposed). A very low starting value (typically < 0.35) is a hallmark of proteins without Trp residues.