MicroStreak® technology

The invention of the MicroStreak® technology enables a fully automated system for streaking biological samples onto agar plates (known also as pre-poured media or PPM plates) and represents a major leap forward for clinical microbiology. This application of the technology has been exclusively licensed to leading France-based company bioMérieux. bioMérieux has named the system PREVI™ Isola, incorporating it into its PREVI™ range of automated laboratory equipment. The PREVI™ Isola is a free-standing unit with a footprint of just 1.4 x 0.9m. The laboratory worker loads a cassette of streaking applicators and multiple stacks of agar plates, as well as racks of patient samples in tubes. The machine accepts a range of the most commonly used sample tubes. The central task performed by PREVI™ Isola is to select the appropriate agar plate type, inoculate each sample onto the plate and streak the sample using a patented, sterile plastic applicator. This ensures a reproducible and superior streaking pattern that standardizes the procedure in the laboratory. The machine also performs a number of non-core tasks that give it greater versatility and value as a laboratory tool. Other advantages of the MicroStreak® technology include:

- Time saving — fast and simple to use
- High throughput
- Bar-code labeling
- Easier, faster plate reading
- Designed for labs worldwide
- Higher yields of bacterial colonies

The streaking pattern produced by the PREVI™ Isola is unique, and quite distinct from the pattern produced by manual streaking. Experiments published in the Journal of Clinical Microbiology have shown that the instrument is not only faster, but more effective than the manual method. It utilises a greater proportion of the agar plate surface, producing on average more colonies than manual streaking. This increases the opportunity to identify pathogens within a mixed bacterial population, and thus could potentially improve diagnostic accuracy. The study also showed that the uniformity of the machine-streaking could be very valuable for the correct diagnosis of urinary tract problems. This requires an accurate count of urine bacteria, which can be difficult with manually streaked plates due to the variation inherent in this procedure.

The MicroStreak® streaking pattern (right) is quite different from the traditional manual streaking pattern (left).  MicroStreak reproducibly gives scientists superior quality and numbers of bacterial colonies.

The MicroStreak® circular streaking pattern (left) is quite different from a manual streaking pattern (right). It reproducibly gives scientists superior numbers of distinct bacterial colonies and hence the opportunity to identify more of the varieties that are present.