Just wondering whether anyone can point me to a research paper which describes how the scoring values are generated by the Bruker software for species identification of bacteria in MALDI-TOF MS. For example, there are countless papers describing the Bruker output score as green (species-level confidence), yellow (genus-level), or red (neither species- nor genus-level confidence). However, none of the papers that I see are discussing how these numbers are actually calculated within the Bruker system. Even the Bruker brochure glosses over the point: "After the acquisition of the spectral data has been completed, a report is generated. The result for each sample is clearly listed under ‘Organism (best match)’ accompanied by the resulting score and an appropriate ‘traffic light’ color scheme." Can anyone point me in the direction of a paper or at least some online information such as wikipedia describing how Bruker came up with these numbers? It's not just an arbitrary number, right?
Another generic description of the scores is in this presentation: "Higher the log (score), higher the similarity between mass spectrum of isolate & the database entry in the reference library."