hello doctor ,see this link may be helpful
https://www.labome.com/method/Cell-Culture-Media-A-Review.html
Hello
Most of the commercially available culture media include phenol red as a pH indicator, which allows constant monitoring of pH [24]. During the cell growth, the medium changes color as pH is changed due to the metabolites released by the cells. At low pH levels, phenol red turns the medium yellow, while at higher pH levels it turns the medium purple. Medium is bright red for pH 7.4, the optimum pH value for cell culture. However, there are certain disadvantages of using phenol red as described below: 1) Phenol red mimics the action of some steroid hormones, particularly estrogen [25]. Thus it is advisable to use media without phenol red for studies using estrogen-sensitive cells like mammary tissue. 2) Presence of phenol red in some serum-free formulations interferes with the sodium-potassium homeostasis. This effect can be neutralized by the inclusion of serum or bovine pituitary hormone in the medium [26]. 3) Phenol red interferes with detection in flow cytometric studies.
Hi: Its dependence on what indicator you are use, you should follow the protocol for preparing this media.
additive enzyme and some regent effect with high heat more than 120 c in autoclave
hi
Phenol red exists as a red crystal that is stable in air. Its solubility is 0.77 grams per liter (g/l) in water and 2.9 g/l in ethanol.[1] It is a weak acid with pKa = 8.00 at 20 °C (68 °F).
A solution of phenol red is used as a pH indicator, often in cell culture. Its color exhibits a gradual transition from yellow (λmax = 443 nm[2]) to red (λmax = 570 nm[3]) over the pH range 6.8 to 8.2. Above pH 8.2, phenol red turns a bright pink (fuchsia) color.[4][5]
Phenol red (pH indicator)
below pH 6.8
above pH 8.2
6.8
⇌
8.2
In crystalline form, and in solution under very acidic conditions (low pH), the compound exists as a zwitterion as in the structure shown above, with the sulfate group negatively charged, and the ketone group carrying an additional proton. This form is sometimes symbolically written as H+
2PS−
and is orange-red. If the pH is increased (pKa = 1.2), the proton from the ketone group is lost, resulting in the yellow, negatively charged ion denoted as HPS−. At still higher pH (pKa = 7.7), the phenol's hydroxide group loses its proton, resulting in the red ion denoted as PS2−.[6]
In several sources, the structure of phenol red is shown with the sulfur atom being part of a cyclic group, similar to the structure of phenolphthalein.[1][7] However, this cyclic structure could not be confirmed by X-ray crystallography.[8]
Several indicators share a similar structure to phenol red, including bromothymol blue, thymol blue, bromocresol purple, thymolphthalein, and phenolphthalein. (A table of other common chemical indicators is available in the article on pH indicators.)
Phenolsulfonphthalein test[edit]
Hi Dr.,see this link may be help you
https://www.labome.com/method/Cell-Culture-Media-A-Review.html
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