Cancerous cell lines have traditionally shown low sensitivity to laboratory or pharmaceutical preparations of botulinum neurotoxin. The work presented here demonstrates that the mouse neuroblastoma/rat glioma hybrid cell line NG108-15 is capable of more sensitively detecting BoNT/A1 than any cell line previously described. This cell line has previously been described to have motor neuron like characteristics, therefore making it a good model to study BoNTs. Differentiation of NG108-15 cells in serum-free medium containing retinoic acid and purmorphamine dramatically increased sensitivity of the neurons lto BoNT/A (EC50=similar to 16 LD50 U). Additional pre-treatment with triasialoganglioside GT1B prior to toxin exposure reduced the EC50 further to similar to 11 LD50 U. Co-culture of the neurons with C2C12 myotubes also significantly increased BoNT/A sensitivity of NG108-15 cells (EC50=26 U) in the absence of differentiation factors. (C) 2012 Elsevier Inc. All rights reserved.