To determine where the tryptophan residue is in relation to the rest of the molecule, four different solution-state conformations (native, monomeric intermediate, associated intermediate, and unfolded) were used and their fluorescence spectra were analyzed. The intensity of the tryptophan fluorescence of native state bGH was significantly lower than that of unfolded bGH, indicating intramolecular fluorescence quenching in the native state. This also supports data that tryptophan is most accessible to all quenchers in the unfolded state because no steric restrictions inhibit quencher-residue interaction. The associated intermediate tryptophan was also observed to be less accessible to quenchers than the monomeric intermediate, probably due to tightly packed molecules in the associated intermediate state. Once this information about tryptophan environment is known, the environments for the surrounding amino acids can be estimated.