2.0 ml of 35 nm EverGreen labeled iron-based superparamagnetic contrast agent packaged in a 2 ml sealed serum bottle. 2 mg Fe/ml having a zeta potential of ~+31 mV. Labeled cells may be visualized using a standard fluorescein filter set. Molday Ion EverGreen has an excitation and emission maxima at 498 nm and 526 nm, respectively.