LANCE® Eu-W1024-ITC Chelate is optimized for the labeling of proteins and peptides at least one primary aliphatic amino group. The labeled compound can be used in homogeneous time-resolved fluorescence resonance energy transfer (TR-FRET) assays (LANCE® assays).

• Isothiocyanate (ITC) activated chelates react primarily with free amine groups such as ones a N-terminus of protein or lysine residues. 
• LANCE® W1024 Series chelates are preferred in most HTS applications due to their lower fluorescent background in TR-FRET assays. 
• For most LANCE™ applications the W1024 series of Eu chelates with active group can be used. Usable pH range 5-11. Under neutral conditions W1024 remains stable in EDTA concentrations up to 20 mmol/L. Allophycocyanin (APC)- or ULight-labeled compounds can be used as acceptors for LANCE® TR-FRET assays.

LANCE® (Lanthanide chelate excite) and LANCE® Ultra are our TR-FRET (time-resolved fluorescence resonance energy transfer), homogeneous (no wash) technologies. One molecule of interest is labeled with a donor fluorophore (a LANCE Europium chelate) and the second molecule is labeled with an acceptor fluorophore [ULight™ dye, allophycocyanin (APC)]. Upon excitation at 320 or 340 nm, energy can be transferred from the donor Europium chelate to the acceptor fluorophore if sufficiently close for FRET (~10 nm). This results in the emission of light at 665 nm (for ULight dye and APC).