Cresol red
Cresol Red (CAS: 1733-12-6; Formula: C21H18O5S; Molar Mass: 382.43 g/mol) is a sulphonphthalein indicator. This yellow-to-red dye is primarily employed as a pH indicator and a tracking dye in various laboratory applications, including gel electrophoresis and biosensor development. Its distinct colour change within a specific pH range makes it valuable for visual endpoint determination in titrations and analytical procedures.
- IUPAC
- o-Cresolsulfonphthalein
- Synonyms
- o-Cresolsulfonphthalein
Electrophoresis Tracking Dye
Cresol Red serves as an effective tracking dye in DNA, RNA, and protein electrophoresis. It migrates at an apparent molecular size comparable to approximately 125 bp DNA in agarose gels, allowing for visual monitoring of sample progression without inhibiting Taq polymerase activity.
pH Indicator
With a pH range of 7.2–8.8, Cresol Red exhibits a distinct colour transition from yellow to red. This property makes it suitable for visually indicating the endpoint in acid-base titrations and for monitoring pH changes in various chemical and biological systems.
Biosensor Development
This indicator dye has found recent application in the development of nanoengineered optical biosensors. It is used in films and fiber optic sensor designs, specifically for detecting urea through pH-sensitive colour changes.
| Molecular weight | 382.43 |
|---|---|
| Empirical formula | C21H18O5S |
| Grade | indicator grade |
| Application | Cresol Red is used as a tracking dye in DNA, RNA (agarose) and protein (polyacrylamide) electrophoresis. In agarose, Cresol Red runs with an apparent molecular size of approx. 125 bp DNA. Cresol Red does not inhibit Taq polymerase. Recently Cresol Red has been used as a pH sensitive indicator dye in nanoengineered optical urea biosensors films and hetero-core structured fiber optic pH sensor. |
| Composition | Dye content, 95% |
Hazard statements
- H315Causes skin irritation
- H319Causes serious eye irritation
- H335May cause respiratory irritation
Precautionary statements
- P261Avoid breathing dust, fume, gas or vapours
- P305IF IN EYES
| Protective equipment | dust mask type N95 (US), Eyeshields, Gloves |
|---|---|
| Water hazard class (WGK, DE) | 3 |
| Hazard codes (EU) | Xi |
| Risk statements (R) | 36/37/38 |
| Safety statements (S) | 26-36 |
Hazard information is provided for guidance. Always consult the product Safety Data Sheet (SDS), available on request, before handling.
| Ph Range | 7.2 - 8.8, yellow to red |
|---|
Documentation
Every batch ships with a Certificate of Analysis covering assay, identity and purity; the grade is confirmed against your enquiry. Safety Data Sheets and technical data sheets are available on request.
Supply & logistics
Samples for technical evaluation; bulk MOQ by grade and packaging. In-stock material ships in 7–10 working days, worldwide, with full export documentation.
What is Cresol Red used for?
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Cresol Red is used as a pH indicator and a tracking dye in gel electrophoresis (DNA, RNA, protein). It is also utilised in the development of optical biosensors and for non-aqueous titrations.
What are the CAS number and formula for Cresol Red?
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The CAS number for Cresol Red is 1733-12-6, and its empirical formula is C21H18O5S.
What grade and purity does Tech Serve Solutions supply?
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Tech Serve Solutions supplies Cresol Red in indicator grade with a dye content of approximately 95%. This product is not supplied as USP, BP, EP, or any pharmacopoeia grade.
How should Cresol Red be handled safely?
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Cresol Red is classified with hazard statements H315 (causes skin irritation), H319 (causes serious eye irritation), and H335 (may cause respiratory irritation). When handling, wear a dust mask type N95, eyeshields, and gloves. Ensure good ventilation and avoid inhaling dust. Refer to the Safety Data Sheet for full guidance.
Is Cresol Red a controlled substance?
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The provided data does not indicate that Cresol Red is a controlled substance.
How is Cresol Red packed and shipped?
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Tech Serve Solutions, as a specialist global supplier and exporter, can provide information on packing and shipping options for Cresol Red upon request, adhering to all relevant regulations.
How can I request a sample or quote for Cresol Red?
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To request a sample or a quotation for Cresol Red, please contact our sales team through the designated channels on the Tech Serve Solutions website.
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