Technical Data
ImmunoTek™ p-Nitrophenyl Phosphate (pNPP), 50X Concentrate, 0.19M
Molecular Biology Storage: 4°CShipping: Blue Ice
ImmunoTek™ p-Nitrophenyl Phosphate (pNPP), 50X Concentrate, 0.19M

Excellent substrate for phosphatase based ELISA assays. It produces a soluble end product which is yellow in color and read at 405nm to 410nm. Both kinetic and end point determinations can be performed. Supplied as a 50X concentrate. Dual component system.

pNPP is the most conventional reagent employed for estimating alkaline phosphatase (AP) activity. It is usually provided in powder or tablet form and dissolved in buffer prior to use. Working concentrations range from 3.5-4.0mM when used for ELISA assays.

After completion of analyte binding to a solid phase and reaction with an AP labeled probe, diluted pNPP Solution is added. Hydrolysis of the phosphate ester liberates p-nitrophenol producing a yellow chromogen with an extinction coefficient of 1.83 x 10e4 mol-1cm-1 at 405nm.

The reaction is linear allowing kinetic assays. Endpoint analysis can be performed by stopping the reaction with strong base and reading the final color at 405nm. Transphorylating agents such as diethanolamine (DEA), 2-amino-2-methyl-1-propanol (AMP) or on some occasions 2-amino-2-methyl-1,3-propanediol (AMPD) are the prevalent buffers.

For maximum activity: dilute in N2600-15

Color and Clarity:
Colorless to slight yellow

Stability (4°C):
To pass specifications

To pass specifications

ELISA Performance:
To pass specifications

Also Available:
N2600: p-Nitrophenyl Phosphate (pNPP)
N2600-10: p-Nitrophenyl Phosphate (pNPP), 50X Concentrate, 0.19M/Liter
N2600-15: p-Nitrophenyl Phosphate (pNPP) Buffer, DEA

CAS Number:
• Exhibits low background levels
• Safe to use - no weighing of hazardous powders
• Save preparation time - use right out of the bottle
• Ultra-low sensitivity
• Minimal lot-to-lot variation

Important Note: This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.
Intended for research use only. Not for use in human, therapeutic, or diagnostic applications.