We dual stained SCD plasma with BRIC25618, which recognises an extracellular epitope on GPA, and BRIC16319, which recognises an intracellular GPA epitope, in order to distinguish right side-out vesicles (BRIC256+ve) and inside-out AVs (BRIC163+ve)17. Here, GYPA is linked to Schnyder corneal dystrophy.