I need an appropriate positive control for WB antibodies I am using to confirm the presence of exosomes in samples. The thing is I am having reproducibility issues, and I would like distinguish whether it is my sample that is the problem because it has no exosomes or if it is the antibodies that aren't working properly. Running a cell lysate of a cell known to express these markers would help me determine this.

Thanks to anyone who took the time to read this and reply.