Based on the LS 200/300/400 systems, the new LS Reloaded series supports both customized formats and microplates. With automatic gain control, the microarray scanners can use different laser and filter combinations in one scan.
The new series of scanners are able to cover an extended dynamic range of intensities by providing a series of gain settings in batch scan option within the experiment. The unique laser beam angle is adjustable and supports high-sensitivity evanescence resonance scanning of glass wavers.
A spokesman for Tecan told DrugResearcher.com: "As well as ELISA and focused biomarker arrays, the technology is suitable for detection of low abundant genes (mRNA, proteins) and/or limited low sample volume from tissue micro dissection."
Microarray scanners typically use one or more lasers and scan dual-fluorophore samples either sequentially or simultaneously. However, simultaneous scanning produces fewer registration errors. LS Reloaded series is available with 2, 3 or 4 lasers and allows simultaneous 2-colour scanning. The LS Reloaded laser scanners enable unattended throughput capability of up to 200 microarray slides or 50 microplates.
In practice, microarray readers can usually detect transcripts with a relative abundance of between one copy in 100,000 and one copy in 500,000, or 3 to 10 copies per cell. The sensitivity required for this low-level fluorescence detection is approximately two-to-five molecules per square micrometer, with a linear dynamic range of five orders of magnitude.
The microarray market is currently seeing a convergence between imaging and scanning. Scanners will likely dominate in the short-term, but imaging is bound to become the principal form of analysis. Scanners may have an edge for very high-density arrays (if required for massive clinical testing). Alternatively, researchers may adopt techniques such as two-photon or near-infrared confocal microscopy endowed with more restricted focus depth and low background.
As microarray usage becomes commonplace, microarray images will join the standard record-keeping photographs of Western blots, agarose gels, or tissue sections. Thus, a general-purpose imager could prove profitable. MiraiBio's FMBIO II, can detect DNA in both agarose gels and sequencing gels, in addition to scanning microarrays. Array reading can be incorporated as a module of operation in many general imagers, but it seems unlikely sophisticated microarray readers will take this all-in-one approach.
Microarray scanners currently on the market include Fujifim Medical Systems FLA-5000 Science Imaging System, Affymetrix's GeneArray Scanner, MiraiBio's FMBIO and Virtek Vision Corp's ChipReader Microarray Scanner.
Tecan's LS Reloaded will be available October 15th 2004 with prices available on application.