Antibiotics are assayed by which method?

Antibiotics are assayed by which method?

• A. Voltammetry
• B. Turbidimetry
• C. Polarimetry
• D. Refractometry

Answer: (B)

Antibiotic potency is determined by how well the compound stops bacterial growth in a broth, and turbidimetry directly measures that effect. By tracking the cloudiness (turbidity) of a bacterial culture after exposing it to different antibiotic concentrations, you can see how growth is inhibited. The more antibiotic present, the less growth occurs, so the culture stays clearer and the optical density decreases. This creates a dose–response curve from which the potency of the antibiotic is derived. Other methods don’t reflect growth inhibition in the same straightforward way: voltammetry is an electrochemical technique, polarimetry measures how light rotates in chiral solutions, and refractometry gauges refractive index. None of these directly quantify how effectively a compound suppresses microbial growth, which is why turbidimetry is used for antibiotic assays.

Antibiotic potency is determined by how well the compound stops bacterial growth in a broth, and turbidimetry directly measures that effect. By tracking the cloudiness (turbidity) of a bacterial culture after exposing it to different antibiotic concentrations, you can see how growth is inhibited. The more antibiotic present, the less growth occurs, so the culture stays clearer and the optical density decreases. This creates a dose–response curve from which the potency of the antibiotic is derived.

Other methods don’t reflect growth inhibition in the same straightforward way: voltammetry is an electrochemical technique, polarimetry measures how light rotates in chiral solutions, and refractometry gauges refractive index. None of these directly quantify how effectively a compound suppresses microbial growth, which is why turbidimetry is used for antibiotic assays.