Neurotoxin quantum dot conjugates detect endogenous targets expressed in live cancer cells.

High affinity peptide neurotoxins are effective agents for integrating technological advances with biological inquiries. Both chlorotoxin (CTX) and dendrotoxin-1 (DTX-1) are peptide neurotoxins demonstrated to bind targets expressed by glioma cancer cells and are suitable ligands for quantum dot (QD) live cell investigations. Here, we present dual labeling of endogenously expressed cellular proteins within living cells utilizing high affinity peptide neurotoxins conjugated to QDs. Multiplexing experiments reveal quantifiable evidence that CTX and DTX-1 conjugated QDs may potentially be used as a live assessment of markers toward identification of cancer cell presence.