Recombinant Mouse Kell Protein, CF

• 6 months from date of receipt, -20 to -70 °C as supplied.
• 3 months, -20 to -70 °C under sterile conditions after opening.

• Assay Buffer: 0.1 M MES, pH 6.5
• Recombinant Mouse Kell (rmKell) (Catalog # 1454-ZN)
• Substrate: MCA-Arg-Pro-Pro-Gly-Phe-Ser-Ala-Phe-Lys(DNP)-OH (Catalog # ES005), 2 mM stock in DMSO
• F16 Black Maxisorp Plate (Nunc, Catalog # 475515)
• Fluorescent Plate Reader (Model: SpectraMax Gemini EM by Molecular Devices) or equivalent

1. Dilute rmKell to 20 ng/µL in Assay Buffer.
2. Dilute Substrate to 20 µM in Assay Buffer.
3. Load 50 µL of the 20 ng/µL rmKell in a plate, and start the reaction by adding 50 µL of 20 µM Substrate.  Include a Substrate Blank containing 50 µL Assay Buffer and 50 µL of 20 µM Substrate.
4. Read at excitation and emission wavelengths of 320 nm and 405 nm (top read), respectively, in kinetic mode for 1 hour.
5. Calculate specific activity:

     *Adjusted for Substrate Blank
     **Derived using calibration standard MCA-Pro-Leu-OH (Bachem, Catalog # M-1975).

• rmKell: 1 µg
• Substrate: 10 µM