How would you evaluate carryover across a robot workflow?

Why

Create a challenge sequence that includes the most demanding reagent or analyte, then one or more blanks at relevant positions. Repeat across tips, channels, deck areas and wash or tip-change conditions. Quantify blank response against the previous high sample and the assay detection threshold using predefined criteria.

Include negative controls, contamination controls and blanks before high samples to distinguish background from carryover. If the signal appears only after a high sample, investigate droplet formation, reused tips, wash efficiency, aerosols, mixing and shared surfaces. Evaluate plate order and any cross-contamination from adjacent wells.

For sensitive PCR, trace nucleic acid contamination separately from liquid volume error. A passing mean blank may hide one contaminated channel, so analyse worst-case locations as well as summary statistics.