Thermo Scientific™

Pierce™ PNPP Substrate Kit

Catalog number:  37620

Related applications:

Protein Assays and Analysis

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Thermo Scientific Pierce PNPP (p-nitrophenyl phosphate) is a colorimetric, soluble substrate of alkaline phosphatase for use in ELISA applications. Our Phosphatase Substrate Kit contains PNPP tablets and a Diethanolamine Buffer to yield more than one liter of substrate. The Diethanolamine Substrate Buffer (Part No. 34064) is also provided individually as a 5X concentrate. The Pierce formulation has an optimal and consistent pH and it is stable even at a 1X concentration.

Features of PNPP (p-nitrophenyl phosphate):

• One-component alkaline phosphatase (AP) substrate
• Absorbance maximum of 405nm
• Develops a yellow hue in solution upon reaction with AP
• Safer to use—contains a non-mercury, non-azide preservative

PNPP (p-Nitrophenyl Phosphate, Disodium Salt) is a widely used substrate for detecting alkaline phosphatase in ELISA applications. When alkaline phosphatase and PNPP are reacted, a yellow water-soluble reaction product is formed. This reaction product absorbs light at 405nm. The substrate is offered in several formats.

Related Products
1-Step™ PNPP Substrate Solution
PNPP Substrate Tablets
PNPP Substrate
For Research Use Only. Not for use in diagnostic procedures.


Product Line: Pierce™
Substrate Properties: Chemical Substrate
Detection Method: Colorimetric
Substrate Type: AP (Alkaline Phosphatase) Substrate
Description: Pierce PNPP Substrate Kit

Contents & storage

Sufficient For: 5mL of typical 1X substrate solution per tablet (525 mL total; approx. 5250 wells at 100 µL per well)
• Diethanolamine Buffer, 225 mL
• PNPP Tablets, 105 tablets (5 mg/tablet)

Store buffer at 4°C and PNPP tablets at -20°C.