WHAT IS PHENOLSULFONPHTHALEIN TEST?
Phenolsulfonphthalein (PSP) is a pH indicator often used in cell biology laboratories. Clinically, phenolsulfonphthalein is used as a test to help diagnose problems or disease of the kidneys. This test determines how effectively your kidneys are working.
Phenolsulfonphthalein synonyms are “phenol red”.
Phenolsulfonphthalein was used by Leonard Rowntree and John Geraghty, in the phenolsulfonphthalein test, to estimate the overall blood flow through the kidney. This was carried out in 1911. It was the first kidney function test but has become obsolete, after about a century of usage.
Phenolsulfonphthalein antimicrobial exists as a red crystal that is stable in the air, with a solubility of 0.77 grams per liter (g/L) in water, and 2.9g/L in ethanol. Phenol red is a weak acid, having a pKₐ=8.00 at 20°C.
A solution of phenol red is used as a pH indicator, often in cell culture. Phenol red neutral color exhibits a gradual transition from yellow to red (over the pH range of 6.8─8.2). And above pH 8.2, phenol red turns to a bright pink color.
Several sources show the structure of phenolsulfonphthalein with the sulfur atom being part of a cyclic group, similar to the structure of phenolsulfonphthalein, although this structure could not be confirmed by x-ray crystallography. Many other indicators share a similar structure to phenol red, including:
- Bromothymol blue.
- Thymol blue.
- Bromocresol purple.
Phenolsulfonphthalein (PSP) with the molecular formula, C₁₉H₁₄O₅S has a molecular weight of 354.4g/mol.
WHAT IS PHENOL RED USED FOR?
The uses of PSP testing are as follows:
- Phenolsulfonphthalein pH indicator is commonly used as an indicator in labs, during titrations to determine the end-points.
- It is commonly used as an indicator in cell cultures.
- Used in-home swimming pool test kits.
- Used in phenolsulfonphthalein tests for examining the overall blood flow through the kidney.
- It has a role as a two-color indicator, an acid-base indicator, and a diagnostic agent.
Phenol red (phenolsulfonphthalein) is being investigated for clinical use, due to its weak estrogen-mimicking actions, in the process of in-vitro fertilization. PSP is also a dye used in automotive coolants.
RISKS/SIDE EFFECTS OF PHENOLSULFONPHTHALEIN TEST
Phenolsulfonphthalein is toxic and may cause sensitization by skin contact; irritation to the eyes, respiratory system, and skin. Accidental ingestion of phenol red may damage your health. Limited evidence exists, stating that the substance may cause irreversible but non-lethal mutagenic effects, following a single exposure.
PHENOL RED INDICATOR PREPARATION & PROCEDURE.
- You will be asked to empty your bladder.
- You will be given phenolsulfonphthalein dye by injection, in your vein or muscles.
- Again, you will be asked to empty your bladder into about 3 containers, at intervals of 15, 30, and 60 minutes, after the ministration of the phenolsulfonphthalein dye.
- The amount of the medicine (PSP) in your urine will be measured using a colorimeter.
- After everything, the results of the test will be studied carefully.
RESULTS OF PSP TESTING
Your doctor will discuss the result of the PSP test with you, after carefully studying it. Typically, the kidney secretes 80% of the phenolsulfonphthalein dye, while the liver secretes the remaining 20%.
The recovery value at 15 minutes after injection is normally about 25─35%, and it is the most significant diagnostic value, since a damaged kidney may be able to remove the phenolsulfonphthalein dye from circulation, give a longer time to do so.
PSP excretion is decreased in several chronic kidney diseases and may be increased in certain liver disorders.
Phenolsulfonphthalein was used in 1911 by Leonard et al, in the PSP test to estimate the overall blood flow through the liver. It was the first kidney function test, and was used for almost a century, but is now obsolete.
- What is phenol red used for?
Phenol red (phenolsulfonphthalein) is used as a pH indicator. A solution of phenol red will have a yellow color at a pH of 6.4 or below, and a pH of 8.2 and above. Phenolsulfonphthalein is used widely in culture media, to identify changes from neutral to acidic pH values. It is typically used in a cell culture of 11mg/L.
- What is the importance of the phenolsulfonphthalein test?
Phenolsulfonphthalein (phenol red) is used in performing a test to help diagnose problems or diseases of the kidneys. This test determines how well your kidneys are functioning.
- Does phenol red have any side effects after the test?
Phenol red (phenolsulfonphthalein), so far, has not been identified with any serious side effects. Nevertheless, phenol red is toxic, and contact with it can cause irritation, which may occur in the respiratory tract, skin, and eyes.
- How does phenolsulfonphthalein behave in the acidic and basic medium?
Phenolsulfonphthalein (phenol red) is a weak acid with pKₐ=8.0 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 to red (over the pH range of 6.8─8.2). And above pH 8.2, phenol red turns to a bright pink color.
- Is phenol red the same or at all similar to phenolphthalein?
Phenolphthalein and phenolsulfonphthalein (phenol red) are not the same but are very similar. Most of their molecules are identical, except for a small group that dangles off the sides of the main structure. Even the reasons for the color changes with pH are the same.