The automation of SDS-PAGE required substantial investment. To lower this barrier, we devised a cost-effective, simple, and general method where samples are loaded on SDS-PAGE gels held by a newly devised "Gel Adaptor" on a general automated liquid handler. In this method, the liquid handler loads samples on the SDS-PAGE gels held at an angle of 80 degrees on the Gel Adaptor so that the samples can be vertically loaded on the narrow paths of the wells of the slanted gels. This method allows the automated liquid handler to load 144 samples on SDS-PAGE gels in approximately 10 min, greatly reducing the time and cost for high-throughput SDS-PAGE analyses.