Comparing SAgAPLP:LABL and cSAgAPLP:LABL binding and IgM-stimulated (BCR-mediated) calcium flux signaling in Raji B cells through flow cytometry assays: (A) Binding kinetics and (B) maximum steady state (max. SS) binding with fSAgAPLP:LABL, fcSAgAPLP:LABL, and fcHA. (C) Calcium flux inhibition: Fluo-4 loaded cells were first pretreated with vehicle (HBSS), SAgAPLP:LABL, or cSAgAPLP:LABL, then stimulated with anti-IgM (αIgM, black arrow) to evaluate signaling inhibition. (D) Relative IgM signaling stimulation following pretreatment; baseline-adjusted values determined from mean steady state values. (E) Calcium flux reduction: Fluo-4 loaded cells were first stimulated with αIgM at ~30 s (black arrow), then treated with vehicle (HBSS), SAgAPLP:LABL, or cSAgAPLP:LABL after ~60 s (black arrow) to evaluate signaling reduction. (F) Percent reduction from IgM-stimulated baseline following sample addition, determined from mean steady state values. Statistical significance was determined by ANOVA followed by Tukey’s post hoc test with p<0.05 and n=3 (*p<0.05, **p<0.01, ***p<0.001, ****p<0.0001). Calcium flux kinetics in (C) and (D) show median Fluo-4 fluorescence values. Robust curve fitting in (A) was performed using sigmoidal nonlinear regression. Calcium flux data was pooled from three independent experiments.