Ustekinumab is an anti-IL-12/IL-23 IgG1κ human monoclonal antibody.

HUVECs are grown on calibrated glass coverslips to a confluency of 80%. Subsequently, cells are incubated with 200 μg/mL Ustekinumab AlexaFluor488 and Briakinumab AlexaFluor594 for 20 min at 37°C, pH 7.3, washed three times, and chased in fresh medium for an additional 20 min before fixation. Antibodies are directly labeled. FcRn binding is quality controlled by SPR analysis. Cells are then counterstained with anti-FcRn monoclonal antibody DVN22, followed by anti-mouse secondary antibodies conjugated to AlexaFluor647. Imaging is performed on a Leica SP8 confocal microscope[2].