PHOSS-RO Sigma-Aldrich


Synonym: inhibitor tablets for phosphatase, phosphatase inhibitor tablets



Related Categories Biochemicals and Reagents, Enzyme Inhibitors, Enzymes, Inhibitors, and Substrates, Protease Inhibitor Cocktails, Protease Inhibitors More...
form   tablet
packaging   pkg of 10 tablets (04906845001)
  pkg of 20 tablets (04906837001)
mfr. no.   Roche
solubility   aqueous buffer: soluble
shipped in   wet ice
storage temp.   2-8°C


General description

PhosSTOP tablets are a proprietary blend of phosphatase inhibitors, formulated as a ready-to-use tablet which dissolves quickly in aqueous solutions (buffers), including buffers containing formalin (for formalin fixation).


Protects proteins against dephosphorylation. Inhibits phosphatase classes such as acid and alkaline phosphatases, as well as serine/threonine (PP1, PP2A, and PP2B) and tyrosine protein phosphatases (PTP) in bacterial, mammalian, yeast, and plant extracts.


PhosSTOP has been used as a component of
• lysis buffer for the lysis of frozen mouse tissue to obtain protein supernatant
•  lysis of bone derived macrophages
•  nuclear extraction buffer for cell lysis and immunoprecipitation

PhosSTOP protects protein extracts against dephosphorylation. The tablets inhibit a broad spectrum of phosphatases such as acidic and alkaline phosphatases, as well as serine/threonine (PP1, PP2A, and PP2B), dual-specificity phosphatases and tyrosine protein phosphatases (PTP) in bacterial, insect, mammalian, yeast, and plant extracts. PhosSTOP Tablets are well suited for the purification and detection of phoshorylated proteins. They are also used to prevent dephosphorylation in formalin-fixed paraffin embedded (FFPE) tissue sections.
PhosSTOP tablets can be applied in combination with cOmplete Protease Inhibitor Cocktail Tablets to simultaneously protect proteins against dephosphorylation and proteolytic degradation. Both inhibitor tablets maintain their activity when used together.
PhosSTOP inhibitors were evaluated for their effect on protein assays. The inhibition shows almost no influence on BCA or Bradford protein assays.

Features and Benefits

Achieve immediate, effective, and convenient inhibition of a broad spectrum of phosphatases across a wide range of sample materials (e.g., mammalian, plant, yeast, and bacteria) with non-toxic PhosSTOP Phosphatase Inhibitor Cocktail Tablets. PhosSTOP is a proprietary blend of phosphatase inhibitors, formulated as a ready-to-use, quick-dissolving, water-soluble tablet.

• Comprehensive protection: Inhibit acid and alkaline phosphatases, as well as serine/threonine (PP1, PP2A, and PP2B) and tyrosine protein phosphatases.
• Safe: Dissolve the non-toxic PhosSTOP Tablets in aqueous solutions and avoid organic solvents (e.g., DMSO).
• Suitable for formalin fixation: Maintain phosphorylation status of proteins in histological sections.
• Convenient: Eliminate the time-consuming search for just the right phosphatase inhibitor.
• Easy to use: Simply drop a quick-dissolving tablet into your buffer.
• Stable: Store stock solutions for 1 month at +2 to +8°C, or for at least 6 months at -15 to -25°C.

For all-inclusive protein protection, combine PhosSTOP with cOmplete or cOmplete ULTRA Protease Inhibitor Tablets to inhibit both phosphatases and proteases.

Preparation Note

Working concentration: 1 tablet per 10 ml cell extract or buffer
Working solution: Solvent is recommended in distilled water or aqueous buffers (including buffers containing formalin).
Dissolve one tablet per 10 ml aqueous buffer. Alternatively, prepare a 10x stock solution in 1 ml dist. water or 100 mM phosphate buffer, pH 7.0. Higher concentrations of stock solutions (e.g., 20x) are possible.
Storage conditions (working solution): 2 to 8 °C

Other Notes

For life science research only. Not for use in diagnostic procedures.

Legal Information

PhosSTOP is a trademark of Roche

Safety & Documentation

Safety Information

NONH for all modes of transport


Certificate of Analysis (COA)

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Protocols & Articles


Protein Stabilization Reagents from Roche

Naturally-occurring proteases and phosphatases can destroy proteins that you spent days isolating. With Roche’s experience in protein isolation, purification, and protein protection against degradati...
Keywords: Affinity chromatography, Cell disruption, Chromatography, Degradations, Immobilization, Phosphorylations, Purification, Tagged proteins


PhosSTOP™ Protocol

PhosSTOP Inhintor: Removal from lysate using dialysis The phosphatase inhibitors included in PhosSTOP Tablets can be deactivated or removed from a lysate using dialysis. Inhibitor binding to phosphat...
Keywords: Cell disruption, Dialysis, Phosphorylations

Peer-Reviewed Papers


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