# Overcoming a false-positive mechanism in RapidFire MRM-based high throughput screening

**Authors:** De Lin, Lesley-Anne Pearson, Shamshad Ahmad, Sandra O’Neill, John Post, Colin Robinson, Duncan E. Scott, Ian H. Gilbert

PMC · DOI: 10.1016/j.slasd.2025.100252 · Slas Discovery · 2025-09-01

## TL;DR

This paper identifies a new false-positive mechanism in a mass spectrometry screening method and proposes a solution to reduce errors in drug discovery.

## Contribution

A novel false-positive mechanism in RapidFire MRM screening is identified, along with a mitigation pipeline.

## Key findings

- A previously unreported false-positive mechanism was discovered in RapidFire MRM-based screening.
- A pipeline was developed to detect and mitigate these false positives effectively.
- The method improves screening accuracy by reducing unnecessary follow-up on erroneous hits.

## Abstract

False-positives plague high-throughput screening in general and are costly as they consume resource and time to resolve. Methods that can rapidly identify such compounds at the initial screen are therefore of great value. Advances in mass spectrometry have led to the ability to screen inhibitors in drug discovery applications by direct detection of an enzyme reaction product. The technique is free from some of the artefacts that trouble classical assays such as fluorescence interference. Its direct nature negates the need for coupling enzymes and hence is simpler with fewer opportunities for artefacts. Despite its myriad advantages, we report here a mechanism for false-positive hits which has not been reported in the literature. Further we have developed a pipeline for detecting these false-positive hits and suggest a method to mitigate against them.

Image, graphical abstract

## Full-text entities

- **Genes:** WDTC1 (WD and tetratricopeptide repeats 1) [NCBI Gene 23038] {aka ADP, DCAF9}
- **Chemicals:** lysine (MESH:D008239), EGTA (MESH:D004533), sucrose (MESH:D013395), carbons (MESH:D002244), DMSO (MESH:D004121), NaCl (MESH:D012965), water (MESH:D014867), Sinefungin (MESH:C006235), formic acid (MESH:C030544), S-adenosylhomocysteine (MESH:D012435), Sepharose (MESH:D012685), Brij-35 (MESH:C515901), GSH (MESH:D005978), S-adenosylmethionine (MESH:D012436), nitrogens (MESH:D009584), Peptides (MESH:D010455), 13C (MESH:C000615229), E. d4-SAH (-)
- **Species:** Severe acute respiratory syndrome coronavirus 2 (no rank) [taxon 2697049], Trypanosoma brucei (species) [taxon 5691]
- **Mutations:** G12C

## Full text

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## Figures

3 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12823550/full.md

## References

18 references — full list in the complete paper: https://tomesphere.com/paper/PMC12823550/full.md

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Source: https://tomesphere.com/paper/PMC12823550