Electrochemiluminescence for Pharmacokinetic Bioanalysis

Pharmacokinetic assays must accurately quantify drug concentrations across a wide range — from high µg/mL levels at Cmax to low ng/mL levels at trough. Traditional ELISA methods, with a typical dynamic range of 2–3 logs, often require multiple sample dilutions to span this concentration range. MSD's 4–5 log dynamic range frequently captures the full PK profile in a single undiluted measurement, reducing dilution-related variability and the need for reanalysis of out-of-range samples.

Advantages of Electrochemiluminescence for PK

  • Wide dynamic range reduces reanalysis: 4–5 logs per analyte — capture Cmax and trough from a single dilution. Fewer out-of-range results means fewer repeat runs and faster data delivery.
  • Non-enzymatic SULFO-TAG detection: no substrate timing, no color development stop steps, no edge effects. ECL signal is generated instantaneously upon electrical stimulation and is stable — plates can be re-read days later.
  • 25 µL sample volume: critical for preclinical rodent PK studies where serial sampling limits plasma volume. A full 10-point PK profile from less total plasma than a single ELISA well requires.
  • High tolerance to sample matrix: ECL detection is not affected by hemolysis, lipemia, or other matrix components that can interfere with optical detection methods.