The Tecan LS Reloaded Scanner is a fluorescent microarray scanning instrument for use with 1”x 3” chips, 3”x 5” plates and standard 96 or 384 well microplates. The scanner is modular in design, with many options to customize its capabilities for user requirements. A maximum of 4 lasers are available, along with a high throughput/autoloader. With these extra features, the user is able to automate multiplex scans for a large numbers of arrays. I base the evaluation of this instrument primarily from the application of protein microarrays using two lasers (red and green).
The mechanical quality of the scanner is above average, possessing a solid feel, but a slightly larger footprint, than scanners of comparable capabilities. However, the many features and high capacity of this instrument compensate for the slightly larger size. The instrument comes with two types of sample holders, one that holds four 1”x 3” slides and one that holds a plate (3”x 5”). The capability of scanning either with the Tecan slide holders or a well plate greatly increases the versatility of the instrument. The one drawback of the scanner is the short focal length of about 5 – 6 mm from the top. The average 15 mm deep well plate must be scanned from the bottom (upside-down), as the depth of the well exceeds the focal length from the top (right-side up). However, clear bottom well plates and substrates are becoming commercially available for reading through the bottom. Otherwise, the carriage movement seems solid and reliable and the casing is of good quality.
The user interface is intuitive, but does take a moderate level of familiarity for optimal operation. The scanner has a variety of scan settings and parameters that the user can adjust to optimize the scan. I felt this was a nice feature and very beneficial for tailoring the scans for the specific applications but found that programming required some learning time. The scanner has three different focusing parameters that must be set to scan the arrays and are initially tricky to figure out, but ultimately very useful for obtaining excellent images. Fortunately, once the settings and parameters for a given application have been set, they can be saved and samples can be scanned with minor adjustments. One aspect of the software I found annoying was an unusual and redundant method of file saving when using autosave option, which I felt could be greatly simplified.
I found the actual scanning function of the instrument to be quite superior to others I have used in the past in terms of image quality and sensitivity. Although the false color system used for viewing the images is not as good as others I have used, within data analysis, the images are excellent. This scanner regularly detects slide objects I normally do not see on other scanners. Scanning can be performed using several focusing and gain control techniques, allowing the user to further customize the scan to their applications. Resolution is 4 um to 40 um and scan speed is relatively fast (2-4 minutes single slide; 12-14 minutes four slides or 40 minutes for 96-well plate). When scanning 96 individual wells with the resolution set at 10 um, focusing on every individual well will take greater than 2 hours, however, scan quality is exceptional.
Overall, this is an expensive instrument, but compared to the cost of comparable scanners as well as the overall excellent results I have obtained, feel it was worth the price.
Daniel J. Schwartz