What is phenol red indicator used for?
Hear this out loudPausePhenol red is an indicator commonly used to measure pH in swimming pool test kits, see e.g. [2]. The goal of this colorSpec vignette is to reproduce the colors seen in such a test kit, for typical values of pool pH.
What color is phenol red at pH 6.8 or below?
yellow
Hear this out loudPausePhenol red is a pH indicator which turns yellow below a pH of 6.8 and fuchsia above a pH of 7.4. If the organism is able to utilize the carbohydrate, an acid by-product is created, which turns the media yellow.
What does phenol red do to cells?
Hear this out loudPausePhenol red is a weak estrogen mimic, and in cell cultures can enhance the growth of cells that express the estrogen receptor.
What color is phenol red at acidic pH?
Hear this out loudPausePhenol red is a water-soluble dye used as a pH indicator, changing from yellow to red over pH 6.6 to 8.0, and then turning a bright pink color above pH 8.1. As such, phenol red can be used as a pH indicator dye in various medical and cell biology tests.
Is phenol red a carcinogen?
Hear this out loudPauseOSHA: No component of this product present at levels greater than or equal to 0.1% is identified as a carcinogen or potential carcinogen by OSHA. Inhalation – May cause respiratory irritation. Inhalation May be harmful if inhaled.
What does it mean when phenol red turns orange?
Hear this out loudPauseAdditionally, phenol red tubes contain an inverted Durham tube. If a bacterium produces a gas during fermentation this tube will trap that gas a a bubble will be observed in the Durham tube. Sometimes an orange color will develop in the tube, this represents a pH > 6.8 and should not be considered positive.
What does it mean when phenol red turns red?
Hear this out loudPauseIt indicates that there is drop in the pH because of the production of the acid by the fermentation of the carbohydrate (sugar) present in the media. Negative:The tube containing medium will remain red, indicating the bacteria cannot ferment that particular carbohydrate source present in the media.
What is the principle of the phenol red broth?
Hear this out loudPausePrinciple: Phenol Red Fermentation medium contains peptone, phenol red (a pH indicator) and the carbohydrate to be tested. Phenol red is yellow at a pH < 6.8 and red at a pH of > 7.4, therefore if a bacterium ferments a sugar to acid a yellow color will develop.
How do you test for phenol red?
Hear this out loudPauseMethod. Aseptically inoculate each test tube with the test microorganism using an inoculating needle or loop. Alternatively, inoculate each test tube with 1-2 drops of an 18- to 24-hour brain-heart infusion broth culture of the desired organism. Incubate tubes at 35-37°C for 18-24 hours.
Is phenol red indicator toxic?
Hear this out loudPauseInhalation May be harmful if inhaled. Causes respiratory tract irritation. Ingestion May be harmful if swallowed. Skin May be harmful if absorbed through skin.
What does it mean when phenol red turns pink?
Hear this out loudPauseWhat is happening in the Phenol Red Broth, when the microorganism turns it a yellow color and there is an air bubble in the inverted test tube? Sugar has been fermented to acid and gas has been produced. A pink color in the Phenol Red broth indicates the microorganism does not have the ability to…
What is the best interpretation of a phenol red broth that has turned orange?
Hear this out loudPauseIf a bacterium produces a gas during fermentation this tube will trap that gas a a bubble will be observed in the Durham tube. Sometimes an orange color will develop in the tube, this represents a pH > 6.8 and should not be considered positive.
Why is phenol red used as a pH indicator?
Phenol red is 3H-2,1-Benzoxathiole 1,1-dioxide in which both of the hydrogens at position 3 have been substituted by 4-hydroxyphenyl groups. A pH indicator changing colour from yellow below pH 6.8 to bright pink above pH 8.2, it is commonly used as an indicator in cell cultures and in home swimming pool test kits.
What happens if you add carbohydrates to phenol red?
The addition of some carbohydrates to the basal medium may result in an acid reaction. To ensure accuracy of interpretation, uninoculated control tubes and/or inoculated Phenol Red Broth Base control tubes should be run in parallel with the fermentation tests.
What is the pH of phenol red broth?
One contains glucose; one contains lactose, and the last contains sucrose. The objective of the exercise is to determine which organisms can utilize each sugar. Phenol red is a pH indicator which turns yellow below a pH of 6.8 and fuchsia above a pH of 7.4.
What is the molecular weight of phenol red?
Phenol red PubChem CID 4766 Synonyms PHENOL RED phenolsulfonphthalein 143-74- Molecular Weight 354.4 g/mol Date s Modify 2021-05-08 Create 2005-03-25