LDV-FITC TFA is a fluorescent peptide, specifically an FITC-conjugated LDV peptide. This compound binds to the α4β1 integrin with high affinity, displaying a Kd of 0.3 nM in the presence of Mn2+ and 12 nM in its absence, when binding to U937 cells. LDV-FITC TFA is useful for assessing α4β1 integrin affinity.