PHENOLSULFONPHTHALEIN- ▸ pH indication: acid-base indicator for the pH 6.4 to 8.2 range
- ▸ Laboratory reagent: indicator and reagent for analytical work
- ▸ Biological staining: reagent for cell-culture media and biological work
A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.
Request SDS →Phenol Red (CAS 143-74-8), also called phenolsulfonphthalein, is a sulfonephthalein supplied as a red-orange powder. It is used as a pH indicator over the approximate range 6.4 to 8.2 and as a laboratory and biological reagent.
Frequently Asked Questions
What is phenol red used for?
Phenol Red (CAS 143-74-8), also called phenolsulfonphthalein, is a sulfonephthalein supplied as a red-orange powder. It is used as a pH indicator over the approximate range 6.4 to 8.2 and as a laboratory and biological reagent, including in cell-culture media.
What does a positive phenol red test indicate?
Phenol red changes color across its transition range (roughly pH 6.4 to 8.2), shifting from yellow under more acidic conditions toward red/pink under more alkaline conditions. A color change therefore indicates a shift in pH across that range; the exact interpretation depends on the specific test protocol in which it is used.
What is the pH range of phenol red?
Phenol red is effective as an acid-base indicator over the approximate range pH 6.4 to 8.2, transitioning from yellow toward red across that span. This makes it common for near-neutral and biological pH monitoring.
What is the chemical formula of phenol red?
Phenol red has the molecular formula C19H14O5S, CAS 143-74-8, and is the sulfonephthalein dye phenolsulfonphthalein. It is supplied as a red-orange powder for indicator and reagent use.
What is the cost of bulk phenol red powder?
Pricing depends on grade, purity, and quantity. Request a bulk quote with your required volume and any grade specification rather than relying on a list price, and we will return current pricing with the CoA and SDS.