Figure 9: “Magnetic extraction” of GPI-proteins. GPI-proteins, such as antibodies and protein analytes, are extracted in the large scale by binding to anti-GPIantibodies coupled to metal beads and subsequent removal of the complexes formed between them and the GPI-proteins from the host cell surface by attraction to an electromagnetic plate. Upon lifting of the electromagnetic plate, the highly enriched GPI-proteins are released with the intact GPI anchor by excess of sugar moieties or as phosphoinositolglycan (PIG)-analytes (with PIG remnant) by cleavage with phospholipase C.