Because its lack of reactive alcohol, aldehyde or ketone groups, THF is less reactive and preserve fluorescence better than other dehydrating solutions.[1][2] After dehydration the sample is rinsed first in dichlormethane (DCM) and finally in dibenzyl ether (DBE) to match the refractive index of tissue and surrounding medium leading to transparent sample. In DBE samples are stored and imaged as well.[3]