Anti-FOXP3 antibody [2A11G9] (ab36607)

Overlay histogram showing Jurkat cells stained with ab36607 (red line). The cells were fixed with 4% paraformaldehyde (10 min) and then permeabilized with 0.1% PBS-Tween for 20 min. The cells were then incubated in 1x PBS / 10% normal goat serum / 0.3M glycine to block non-specific protein-protein interactions followed by the antibody (ab36607, 1µg/1x10⁶ cells) for 30 min at 22ºC. The secondary antibody used was DyLight® 488 goat anti-mouse IgG (H+L) (ab96879) at 1/500 dilution for 30 min at 22ºC. Isotype control antibody (black line) was mouse IgG1 [ICIGG1] (ab91353, 2µg/1x10⁶ cells) used under the same conditions. Acquisition of >5,000 events was performed. This antibody gave a positive signal in Jurkat cells fixed with 80% methanol (5 min)/permeabilized with 0.1% PBS-Tween for 20 min used under the same conditions.

All lanes : Anti-FOXP3 antibody [2A11G9] (ab36607) at 1/1000 dilution

Lane 1 : Human truncated Foxp3 recombinant protein
Lane 2 : HEK293 cell extract

Lysates/proteins at 2 µg/ml per lane.

Predicted band size: 47 kDa
Observed band size: ~50-53 kDa why is the actual band size different from the predicted?