Positive Samples: Human plasma, Mouse spleen Immunogen sequence: MSSAAGFCAS RPGLLFLGLL LLPLVVAFAS AEAEEDGDLQ CLCVKTTSQV RPRHITSLEV IKAGPHCPTA QLIATLKNGR KICLDLQAPL YKKIIKKLLE S. Platelet factor-4 is a 70-amino acid protein that is released from the alpha