Recombinant Human NAGLU 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 Sodium Citrate, 0.25 M NaCl, pH 4.5
• Recombinant Human alpha ‑N‑acetylglucosaminidase/NAGLU (rhNAGLU) (Catalog # 7096-GH)
• Substrate: 4-Nitrophenyl-N-acetyl-alpha -D-glucosaminide (Sigma, Catalog # N-8759), 5 mM stock in deionized water
• NaOH, 0.2 M stock in deionized water
• 96-well Clear Plate (Costar, Catalog # 92592)
• Plate Reader (Model: SpectraMax Plus by Molecular Devices) or equivalent

1. Dilute rhNAGLU to 3 ng/μL in Assay Buffer.
2. Dilute Substrate to 3 mM in Assay Buffer.
3. In a plate combine 50 μL of rhNAGLU and 50 μL of 3 mM Substrate. Include a Substrate Blank containing 50 μL Assay Buffer and 50 μL of 3 mM Substrate.
4. Seal plate and incubate at 37 °C for 20 minutes.
5. Add 100 μL of 0.2 M NaOH to each well to stop the reaction and develop the color.
6. Read absorbance in endpoint mode at 402 nm.
7. Calculate specific activity:

     *Adjusted for Substrate Blank
     **Using the extinction coefficient 17700 M^-1cm^-1
     ***Using the path correction 0.6 cm

• rhNAGLU: 0.150 μg
• Substrate: 750 μM