Electrophoresis is actually the wrong answer since PBS should be done first in the pt without a newborn screen (home birth, immigrant status, etc). I don't see any cards that address this. I don't think it warrants a new card, so adding to the Extra of this card (which is already tagged with the AMBOSS QID) should suffice.
Related - electrophoresis is considered a confirmatory test used when a screening test (typically newborn screen, though also seems PBS in older children without newborn screen). https://next.amboss.com/us/article/GT0BH2#Y4930db28cf52bfcc7ff741cbfa43f293
Source: AMBOSS - #AMBOSS::L90wLR
Merged other suggestion that changed the text field to include peripheral blood smear as screening test with electrophoresis as confirmation.