Fig 2: GCase antibody screening by immunoprecipitation on HAP1 lysates.HAP1 lysates were prepared, and immunoprecipitation was performed using 1 mg of lysate and 2.0 μg of the indicated GCase antibodies pre-coupled to Dynabeads protein A or protein G. Samples were washed and processed for western blot with the anti-GCase ab55080* diluted at 1/500 or A19057** at 1/1000. The Ponceau stained transfers of each blot are shown. SM=4% starting material; UB=4% unbound fraction; IP=immunoprecipitate, HC= antibody heavy chain. **= recombinant antibody, *= monoclonal antibody.

Fig 3: GCase antibody screening by immunofluorescence in RPE-1 cells.RPE-1 WT and GBA1 KO cells were labelled with a green or a far-red fluorescent dye, respectively. WT and KO cells were mixed and plated to a 1:1 ratio on coverslips. Cells were stained with the indicated GCase antibodies and with the corresponding Alexa-fluor 555 coupled secondary antibody including DAPI. Acquisition of the blue (nucleus-DAPI), green (WT), red (antibody staining) and far-red (KO) channels was performed. Representative images of the merged blue and red (grayscale) channels are shown. WT and KO cells are outlined with green and magenta dashed line, respectively. When an antibody was recommended for immunofluorescence by the supplier, we tested it at the recommended dilution. The rest of the antibodies were tested at 1 and 2 μg/ml, and the final concentration was selected based on the detection range of the microscope used and a quantitative analysis not shown here. Antibody dilutions used: ab125065** at 1/50, ab128879** at 1/200, ab309228** at 1/500, ab309229** at 1/500, ab55080* at 1/1000, 2020A4849* at 1/500, P1AM1914-001-28* at 1/500, ABCD_AR148** 1/100, ABCD_AR150** at 1/100, A19057** at 1/500, NBP2-66871** at 1/1000, MAB7410* at 1/500, 88162** at 1/500, GTX101267 at 1/100, GTX114073 at 1/700, G4171 at 1/1000, 27972-1-AP at 1/300, MA5-26589* at 1/1000, MA5-26591* at 1/1000, MA5-32591** at 1/1000, MA5-35236** at 1/400, and MA5-38382** at 1/200. Bars = 10 μm. **= recombinant antibody, *= monoclonal antibody.

Fig 4: GCase antibody screening by western blot.Lysates of HAP1 WT and GBA1 KO were prepared, and 30 μg of protein were processed for western blot with the indicated GCase antibodies. The Ponceau stained transfers of each blot are presented to show equal loading of WT and KO lysates and protein transfer efficiency from the acrylamide gels to the nitrocellulose membrane. Antibody dilutions were chosen according to the recommendations of the antibody supplier. Antibody dilutions used: ab125065** at 1/100, ab128879** at 1/1000, ab309228** at 1/200, ab309229** at 1/200, ab55080* at 1/500, 2020A4849* at 1/1000, P1AM1914-001-28* at 1/1000, ABCD_AR148** 1/50 (1 μg/mL), ABCD_AR150** at 1/20, A19057** at 1/1000, NBP2-66871** at 1/500, MAB7410* at 1/500, 88162** at 1/100, GTX101267 at 1/100, GTX114073 at 1/1000, G4171 at 1/1000, 20622-1-AP at 1/100, 27972-1-AP at 1/1000, MA5-26589* at 1/100, MA5-26591* at 1/100, MA5-32591** at 1/1000, MA5-35236** at 1/1000, MA5-38382** at 1/1000, and MA5-52914** at 1/1000. Predicted band size: 59.7 kDa. **= recombinant antibody, *= monoclonal antibody.