CAS 9003-53-6 appears in our catalog under these names: Polystyrene latex microsphere, 1 micron, 10 wt% dispersion i, Polystyrene latex microsphere, 2 micron, 10 wt% dispersion i, Polystyrene standard, M.W. 1,300, Mw/Mn 1.10 , Polystyrene standard, M.W. 2,200, Mw/Mn 1.06 , Polystyrene standard, M.W. 3,350, Mw/Mn 1.10 . Offered by: Thermo Scientific (Alfa Aesar). Available pack sizes: 15ml, 1g, 1g , 500mg, 10g, 50g, 10ml, 5ml.