Stop Solution for AP Substrates (STOPP)
Stop Solution for AP Substrates (STOPP) is a dry powder for use with pNPP-based colorimetric substrates. To use, reconstitute with DiH2O. STOPP is compatible with our pNPP-based alkaline phosphatase substrate, pNPP 1-Component AP Microwell Substrate. This product is suitable for all endpoint ELISAs using an AP substrate for color development of an AP-conjugate.
Stop Solution for AP Substrates (STOPP)
Stop Solution for AP Substrates (STOPP) is a dry powder formulation for use with AP substrates, such as pNPP. To use, reconstitute powder with DiH2O. STOPP is compatible with our pNPP-based alkaline phosphatase substrate pNPP 1-Component AP Microwell Substrate. This product is suitable for all endpoint ELISAs using an AP substrate for color development of an AP-conjugate.
pNPP substrates react with alkaline phosphatase yielding a soluble yellow reaction product. Stop Solution for AP Substrates stabilizes the reaction for one hour and does not change the color or the absorbance of the yellow chromogen. The absorbance is read at 405 nm to 420 nm.
Larger volumes are available upon request.
Room temp
Domestic: Overnight Delivery; International: Priority Shipping
4 - 5.5 at 10 g/l at 23°C (73°F)
Dry Powder
United States
- Reconstitute STOPP by adding 100 mL DiH2O and mix well.
- Add stop solution to plate well. Equal volumes of stop solution and AP microwell substrate should be used. We recommend using 100 µL of pNPP substrate (SUBP) and 100 µL of STOPP per well. The stopped reaction is stable for 1 hour.
- Read absorbance at 405-420 nm within 60 minutes. For best results, sample absorbance should be monitored and stopped before values exceed 2.5 OD units.