Extracting DMR parameters for effective similarity analysis. (a) Representative DMR signals of opioid ligands in native SH-SY5Y cells. The data represents the mean ± s.d. of 2 independent measurements, each in duplicate (n = 4). Responses at three time points (3 min, 9 min, and 30 min post-stimulation) were extracted to represent each DMR signal. The solid arrow indicates the time when ligands were added (t =0). (b) A colored heat map of opioid ligand-induced DMR in native SH-SY5Y cells based on the responses at the three time points. (c) A colored heat map based on the real time DMR signals of all opioid ligands that gave rise to a detectable DMR. The real time responses showed was reduced to every minute. Three time domains were evident.