Monopotassium Phosphate: Uses, Applications & Buying Guide for Canadian Labs and Manufacturers
Monopotassium phosphate, KH₂PO₄, is a reliable buffering agent and nutrient source used widely in microbiological and culture media. Third Space Bio supplies monopotassium phosphate at practical prices, giving labs a dependable, well-characterized phosphate and potassium source for routine media prep.
At a glance
| CAS Number | 7778-77-0 |
|---|---|
| Formula | KH₂PO₄ |
| Common name | Monopotassium phosphate, potassium dihydrogen phosphate, MKP |
| Pack sizes | 500 g ($30), 1 kg ($46), 2 kg ($80) |
| Ships from | Peterborough, ON — Canada-wide delivery |
Applications
Buffering agent
Monopotassium phosphate is a component of phosphate buffer systems, helping hold pH steady in the mildly acidic-to-neutral range that many microbiological media require.
Nutrient source in culture media
Beyond buffering, it supplies both phosphate and potassium — two elements essential to microbial metabolism and growth — making it a common inclusion in defined and semi-defined media recipes.
Microbiological research
Its combination of buffering capacity and nutrient value makes monopotassium phosphate a frequent, low-drama ingredient across a wide range of standard media formulations used in academic and applied microbiology.
Where it fits for food, pharma & research buyers
Monopotassium phosphate's primary market is research and institutional labs, where it's a routine reorder item for anyone running standard microbiological media. Its commercial footprint outside research is smaller than dextrose or citric acid, though the compound does see some use in food and specialty fertilizer contexts at large — worth noting for outreach, though Third Space Bio's product is supplied for laboratory and research use, and the university and lab email list remains the core audience for this product.
Monopotassium phosphate vs. other phosphate buffers
| Compound | Buffering range | Typical use case |
|---|---|---|
| Monopotassium phosphate (KH₂PO₄) | Mildly acidic side of phosphate buffer range | Standard media component, often paired with K₂HPO₄ |
| Dipotassium phosphate (K₂HPO₄) | Mildly alkaline side of phosphate buffer range | Combined with KH₂PO₄ to fine-tune buffer pH |
| Sodium phosphate buffers | Similar range, sodium-based | Used when potassium content needs to be avoided or minimized |
Most phosphate buffer systems use monopotassium and dipotassium phosphate together — the ratio between the two sets the final buffer pH, which is why both often appear side by side in a media recipe.
Frequently asked questions
Mainly as a buffering agent and nutrient source in microbiological culture media, supplying both phosphate and potassium.
They're the two forms of potassium phosphate salt, differing in how many hydrogen ions are bound — used together, they create a tunable buffer system across a useful pH range.
Chemically related, but Third Space Bio's product is manufactured and tested for laboratory and research use rather than agricultural application.
In a cool, dry place in its original container — it's stable under normal lab storage conditions.
See also: Reagents for Labs & Universities and Reagents for Craft & Hobbyist Fermentation Projects.
Browse pack sizes and order Monopotassium Phosphate directly — part of Third Space Bio's mission to make reliable reagents accessible, not a bottleneck, for Canadian research and innovation.
