Validation of an ELISA method for screening methadone in postmortem blood

Area of Science:

• Forensic Toxicology
• Analytical Chemistry

Background:

• Accurate detection of methadone in postmortem specimens is crucial for forensic investigations.
• Existing screening methods require validation for reliability and efficiency.

Purpose of the Study:

• To evaluate the performance of Venture Labs' enzyme-linked immunosorbent assay (ELISA) for methadone detection in postmortem samples.
• To compare ELISA results against established gas chromatographic-mass spectrometric (GC-MS) methods.

Main Methods:

• Analyzed 120 postmortem specimens (61 positive, 59 negative screens) using Venture Labs ELISA and liquid-liquid basic extraction with GC-MS.
• Confirmed positive results and analyzed negative samples using solid-phase extraction with GC-MS-SIM and deuterated internal standards.
• Assessed intra- and interassay precision of the ELISA at a 50 ng/mL cut-off.

Main Results:

• The Venture Labs methadone ELISA demonstrated high accuracy when compared to GC-MS.
• Sensitivity was 96.7%+/-2.3% and specificity was 98.3%+/-1.7% relative to GC-MS.
• Validated the screening capabilities of both ELISA and GC-MS methods.

Conclusions:

• Venture Labs' ELISA is a reliable and accurate method for screening methadone in postmortem specimens.
• The assay's performance supports its use in forensic toxicology workflows.