pH Indicators

Cat. No.

A88874

CAS No.

96-97-9

2-Hydroxy-5-nitrobenzoic acid, 99%

Synonyms: Anilotic acid; 99%

2-Hydroxy-5-nitrobenzoic acid is a pH indicator and analytical standard commonly utilized in high-performance liquid chromatography (HPLC). This compound exhibits key biological activity as a detection agent for heavy metals and plays a role in the investigation of phenolic compound oxidation. Its applications in chemical research make it a valuable reagent for various analytical processes.

Cat. No.

A89197

CAS No.

5423-07-4

Nitrazine yellow

Synonyms: Nitrazine paper; Phenaphthazine

Nitrazine Yellow is an acid-base indicator that exhibits a distinct color transition from yellow to blue within the pH range of 6.0 to 7.0. This property makes it a valuable tool for monitoring pH changes in various biological and chemical experiments. Nitrazine Yellow is widely utilized in life science research, particularly in studies involving pH-dependent reactions and processes.

Cat. No.

A89294

CAS No.

596-01-0

alpha-Naphtholphthalein

Alpha-Naphtholphthalein is a pH indicator that transitions from light yellow at pH 6 to a clear color change towards light green-blue as pH increases. Its sensitivity to variations in acidity makes it ideal for applications in biomedical research, particularly in the development of medical supplies for wound pH monitoring. This compound can be embedded in cotton-blend fabrics to enhance the functionality of items such as medical gauze, hospital gowns, and compression bandages.

Cat. No.

A90031

CAS No.

60-11-7

Methyl yellow

Synonyms: Solvent Yellow 2; Dimethyl yellow

Methyl yellow is a pH indicator that exhibits a color change from red to yellow as pH levels rise above 4.0. This compound is widely utilized in laboratory settings to monitor acidity and alkalinity in various aqueous solutions. Its distinct colorimetric response makes it an effective tool for analytical and educational applications in chemistry and biochemistry.

Cat. No.

A90160

CAS No.

76058-33-8

Ethyl red, 98%

Synonyms: Diethyl red; 98%

Ethyl Red is a pH indicator that exhibits a color change between pH 4.0 and 6.0, transitioning from red to yellow as acidity decreases. This compound is primarily utilized in titrations and various laboratory applications for visualizing pH changes in solutions. Its reliable and distinctive colorimetric response makes it suitable for analytical chemistry and biological studies requiring precise pH measurements.

Cat. No.

A90402

CAS No.

102185-52-4

Bromochlorophenol Blue sodium salt

Bromochlorophenol Blue sodium salt is a pH-indicating dye that exhibits acid-sensitive properties. This compound is widely used in various biochemical assays and laboratory applications to monitor pH changes in solution. Its color transition occurs within a pH range of approximately 3.0 to 4.6, making it suitable for applications in analytical chemistry and microbiology.

Cat. No.

A90898

CAS No.

63451-28-5

Methyl red hydrochloride

Methyl red hydrochloride is an azo dye primarily utilized as a pH indicator. It exhibits distinct color changes from red at pH 4.4 to yellow at pH 6.0, making it valuable for monitoring pH levels in various biological and chemical experiments. Its applications span across microbiology, pharmaceuticals, and environmental testing, where precise pH measurements are crucial.

Cat. No.

A91799

CAS No.

62625-31-4

m-Cresol purple sodium

Synonyms: Metacresol purple sodium

m-Cresol purple sodium is a pH indicator primarily used in biological research and analytical chemistry. This compound transitions from yellow to blue within the pH range of 7.5 to 9.0, making it an effective tool for assessing pH in various experimental setups. Its precise colorimetric response aids in determining the acidity or alkalinity of solutions, facilitating studies in enzymatic reactions, culture media preparation, and environmental monitoring.

Cat. No.

A91882

CAS No.

62625-30-3

Bromocresol purple sodium

Bromocresol purple sodium is a pH indicator that exhibits a color transition from yellow to purple within the pH range of 5.2 to 6.8. This reagent is utilized for detecting yeast cells that exhibit plasma membrane damage and for quantifying serum albumin concentrations. Its applications are vital in biochemical assays and clinical diagnostics, providing reliable and sensitive measurements in various research settings.

Cat. No.

A92728

CAS No.

1393-92-6

Litmus

Litmus is a pH indicator that exhibits a color transition from red at pH 4.5 to blue at pH 8.3. It is widely used in various laboratory applications for assessing acidity and alkalinity in biological and chemical experiments. Litmus serves as a valuable tool in titration processes, environmental testing, and educational demonstrations related to acid-base chemistry.

Cat. No.

A93650

CAS No.

518-51-4

Phenolphthalein (disodium), 95%

Phenolphthalein (disodium) is a pH indicator that exhibits significant colorimetric changes from acidic to alkaline environments. Primarily utilized in titrations and pH determination, this compound transitions from colorless in acidic conditions to pink in neutral and basic solutions. Its reliability in analytical chemistry makes it an essential reagent for various laboratory applications, including educational demonstrations and quality control experiments.

Cat. No.

A94426

CAS No.

145-50-6

α-Naphtholbenzein

Synonyms: p-Naphtolbenzein

α-Naphtholbenzein is a pH indicator that exhibits colorimetric changes in response to pH variations. It is widely utilized in acid-base neutralization reactions, titrations, and pH measurement, providing a reliable method for assessing the acidity or alkalinity of solutions. Its distinctive color transition enhances the visibility of changes in pH, making it valuable for various analytical applications in chemical research.

Cat. No.

B10990

CAS No.

76-60-8

Bromocresol green

Bromocresol green is a pH-sensitive triphenylmethane dye primarily utilized as a pH indicator. It exhibits a color change from yellow in acidic conditions (pH = 4.15) to blue in basic environments, with maximum absorption at 435 nm and 615 nm, respectively. This dye is extensively applied in biochemical analysis for determining protein and albumin concentrations in serum, as well as assessing creatinine levels and evaluating cell viability. Its reliable colorimetric properties make it a valuable tool in various research and clinical settings.

Cat. No.

B11000

CAS No.

493-52-7

Methyl red

Methyl red is an azo dye that functions as a pH-sensitive acid-base indicator with a pKa of 5.1. It facilitates visual determination of titration endpoints by undergoing reversible structural changes related to protonation (red at pH 6.2). Methyl red is extensively utilized in acid-base titrations and for monitoring buffer pH in biochemical research.

Cat. No.

B21482

CAS No.

115-40-2

Bromocresol purple

Bromocresol purple is a pH indicator that exhibits a color transition from yellow to purple as pH levels rise from 5.2 to 6.8. This compound is utilized in various applications, including the detection of yeast cells with compromised plasma membranes and the quantification of serum albumin concentrations, making it valuable in biochemical and clinical research.