There is a growing recognition within the lab industry that MALDI-ToF may be a transformative technology. However, some commercial laboratories have not adopted it yet as an exclusive or primary means for identification of bacteria, yeast, and mycobacteria. Many industry leaders believe this is a missed opportunity.
Benefits: Identification with MALDI-ToF is a relatively simple process. Once a slide has been prepared, it is introduced into a high-vacuum environment, where the sample is ionized with a laser burst that releases proteins. These proteins are then accelerated using an electric charge, and the time of flight is recorded. At the end of travel, the proteins are detected with a sensor. The sensor then creates a spectrum representing the protein makeup for each sample. Identification is made when the spectrum from a sample is compared against a large database of spectra of characterized bacteria, yeast, and mycobacteria. The process can reduce the time needed for identification and diagnosis from days to hours. The easiest way to see the value of MALDI-ToF for patient care is to think of it in terms of specific life-threatening infections where the time from initial infection, to diagnosis, to treatment is highly correlated to patient morbidity.
Limitations: Some organisms may require repeat analysis and additional processing, and some closely related organisms are not differentiated and may cause challenges with identification. The technique also is generally not useful for direct testing of clinical specimens. Finally, the initial purchase price of the equipment is high, which may limit the types of labs that can adopt it.
Conclusion: After weighing the benefits and limitations of MALFI-ToF, an increasing number of commercial laboratories will likely be making efforts to incorporate it as their primary means for identification of bacteria, yeast, and mycobacteria. When it happens, they will be designing a new workflow to optimize the technology and ensure that results get from the lab to clinicians and patients quickly.