dvr Phenol Red Indicator Solution

Phenol Red Indicator Solution is used as a pH indicator. The sodium salt of phenol red is used widely in culture media to identify changes from neutral to acidic pH values.

Technical Specifications:


Physical State

: Liquid


: Red to orange


: Odorless


: 7-8

Specific Gravity

: 1.0

Solubility in water

: Soluble


It is typically used in cell culture media at 11 mg/L. A solution of phenol red will have a yellow color at a pH of 6.4 or below and a red color at a pH of 8.2 and above.Phenol red in tissue culture media can act as a weak estrogen, especially with human breast cancer cells. Lipophilic impurities, not the phenol red dye itself, account for the estrogenic activity. 95-99% of these impurities can be removed from the sodium salt of phenol red with a reduction in estrogen-like activity.

Using Procedure:

Preparation Instructions

This product is a sterle filtered 0.5% solution of tissue culture grade phenol red in Dulbecco,s phosphate buffered saline without magnesium and calcium.

An indicator solution can be formed by dissolving 0.1 g of phenol red in 14.20 ml of 0.02 N NaOH and diluted to 250 ml with deionized water. Phenol red can be used to measure hydrogen peroxide in cultured macrophages in multiwell plates. Assays used 2 units of peroxidase/100 ml volume with 0.5 mM phenol red, pH 7 at 37 °C. The reaction was stopped and color developed by adding 10 ml of 1 N NaOH and reading the absorption of the oxidized phenol red at 600-610 nm. Calculations were accomplished by comparison to a standard curve of hydrogen peroxide.

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