Description

Phenol Red CAS NO 143-74-8 is a synthetic, water-soluble triphenylmethane dye widely recognized as a crucial pH indicator in biological and chemical research. Its distinct color transition from yellow (acidic) to red (basic) around pH 6.8-8.2 makes it an indispensable tool for monitoring biochemical reactions and culture media conditions. This high-purity compound is essential for laboratories, pharmaceutical manufacturers, and biotechnology firms requiring precise and reliable pH visualization in cell culture, microbiology, and diagnostic applications.

Application

• Cell Culture & Microbiology: As a visual pH indicator in cell culture media (e.g., DMEM) to monitor metabolic activity and contamination.
• Diagnostic Kits & Reagents: A key component in urine analysis strips and other clinical diagnostic tests to determine pH levels.
• Biochemical Research: Used in enzyme assays and buffer solutions to track pH changes during biochemical reactions.
• Water Quality Testing: Employed in laboratory settings for the preliminary assessment of water sample alkalinity or acidity.
• Pharmaceutical Manufacturing: For in-process checks and quality control of fermentation processes and other pH-sensitive production steps.
• Educational Laboratories: A standard reagent for teaching acid-base chemistry and titration principles in academic settings.

Basic Information

Product Name	Phenol Red
CAS No.	143-74-8
Molecular Formula	C19H14O5S
Molecular Weight	354.38 g/mol
Synonyms	Phenolsulfonphthalein; PSP; 4,4'-(3H-2,1-Benzoxathiol-3-ylidene)bis-phenol S,S-dioxide; Phenol Red Sodium Salt; 3,3-Bis(4-hydroxyphenyl)-3H-2,1-benzoxathiole 1,1-dioxide; Phenolsulfonephthalein; Sulfonphthal
EINECS	205-609-7

Quality Control

Our Phenol Red is manufactured under a strict quality management system. Each batch is subjected to comprehensive analytical testing, including identification, purity assay, and impurity profiling, to ensure it meets the high standards required for sensitive biological and diagnostic applications. Certificates of Analysis (COA) detailing specific results for parameters such as absorbance, pH transition range, and heavy metal content are available upon request to support your regulatory and quality assurance needs.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at a controlled room temperature (15-25°C). Keep away from incompatible materials and moisture to ensure long-term stability.

Specification

Item	Specification
Appearance	Dark Red to Red-Brown Powder
Identification (IR)	Conforms
Assay (HPLC)	≥ 95.0%
pH Transition Range	6.8 (Yellow) to 8.2 (Red)
Loss on Drying	≤ 5.0 %
Residue on Ignition	≤ 0.5 %
Heavy Metals (as Pb)	≤ 20 ppm
Absorbance (A430/A558)	1.20 - 1.30

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.