Scatterplot of the mean SA-647 versus mean GFP fluorescence calculated for each GFP + cell detected across 10 FOVs treated with either biotin + Ca 2+ ( n = 293 cells; two-tailed Pearson’s R = 0.72, P = 1.5 10 -47 ) or biotin - Ca 2+ ( n = 332 cells; two-tailed Pearson’s R = 0.78, P = 3.7 10 -69 ).