Fluorescein

May be stored at 4 °C for short-term only. For long-term storage and to avoid repeated freezing and thawing, aliquot and add glycerol (40-50%). Freeze at -20 °C. Aliquots are stable for at least 12 months at -20 °C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.

Recognizes Fluorescein. Assay by immunoelectrophoresis resulted in a single precipitin arc against anti-goat serum and fluorescein conjugated BSA. No reaction was observed against anti-pepsin or anti-goat IgG F(c).