“Maldi-tof: Taking the fun out of External QC”

With regards to bacteriology, Maldi-tof has somewhat taken the fun out of External Quality Control programmes, particularly with regards to organism identification (you might say external QC was never much fun in the first place).

No longer do we need to sweat for days over some obscure, biochemically inert organism, looking up the textbooks as we go along for inspiration, and consulting anyone and everyone.

In my short experience with Maldi-tof it is generally very accurate, apart from the odd caveat which are generally well known anyway (eg Shigella & E. coli; Strep. pneumoniae & S. mitis)

So the external QC results are now as a consequence often very good, and we can give ourselves a pat on the back, but do we need to move the bar yet higher?

Maldi-tof may trigger a move away from traditional external QC programmes and direct focus on interpretation of mixed cultures, ascertaining pathogenicity of bacteria isolated from different sites, appropriate result comments, and pre and post analytical errors. This would be good for several reasons, not only because it more accurately reflects our day to day work, but such QC is also more interesting and more challenging, possibly triggering more healthy debate also.

I am not saying that organism identification should be ignored completely by external QC programmes, but bacteriology has always been much more than that, and QC programmes should reflect this….


Apologies for the technical problems with the website yesterday. I contacted the web hosting company last night and they did what all the best IT people do…., turn the system off and switch it back on again..!

3 thoughts on ““Maldi-tof: Taking the fun out of External QC”

  1. I do feel like I am cheating by putting the organism on the Maldi-tof, but it is useful when patience is wearing a little thin (I do give it a go the old fashioned way first). Though one of the last ones we had threw up an organism I hadn’t heard of, nor could find any details on my preferred textbook “Google”. The Maldi-tof was right, though.

    1. Thanks for comments Amber & Tim. It will interesting to see how systems like Maldi-tof affect both the training and assessment of trainees. In 10 years time, will they still be taught the old fashioned bacteriological ID methods or will such methods eventually disappear from the syllabus…?

  2. I’ve looked at MALDI-TOF. It is fairly accurate for a ‘phenotypic’ system, and very fast. There is part of me that laments at the loss of the old school approach, but given the number of IDs now required of a typical lab, such technology is advantageous.

    The main downside is the size (if you look at something like the bioMerieux system), which could cause a problem for smaller labs.

    At the moment I’m using the Biolog Omnilog, which is generally OK. The limitation will all systems is the database.

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