Transfer the whole blood sample to be used for electrophoresis into an eppendorf tube. Ensure the tube is properly closed.
Freeze this sample in a freezer suitable for the storage of organic materials such as blood, at -20 degrees centrigrade. Store until completely frozen (a few hours or perhaps overnight).
Defrost the sample, without vortexing or mixing, and remove the supernatant; this is the hemolysate that will be used for electrophoresis.
Add the buffers most suited to the gel and electrophoresis conditions to be to run the supernatant sample.
Load and run the gel electrophoresis experiment according to the equipment and gel being used.