CRi CRi

Skip to content

Maestro™ FAQs

  • Why is Maestro the most sensitive system for in-vivo imaging?

    Maestro is the most sensitive system because it effectively removes autofluorescence from the image, and utilizes advanced algorithms to ensure accurate unmixing. The limiting factor for sensitivity for in vivo fluorescence detection in any wavelength regime is the interference from the ubiquitous tissue autofluorescence. Since autofluorescence emits at the same wavelengths as fluorophores-of-interest, it is necessary to separate, or unmix, the two - and in doing so, greatly increase contrast and sensitivity.

  • What is multispectral imaging?

    Multispectral imaging is an advanced imaging technique which acquires images where each pixel contains a full spectrum (5 to 20 data points) of the light in that spot, rather than the typical 3 data points (red, green and blue) found in an RGB image. Multispectral imaging allows much more quantitative and sensitive measurement of subtle differences in spectral emissions, which in turn is what provides the increased sensitivity from unmixing.

  • Which fluorophores can I use in Maestro?

    Maestro was designed to be able to image any fluorophore which emits above 500 nm, including GFP, RFP, all of the Alexa Fluor® dyes, ICG, etc.

  • How quickly can I acquire images?

    The acquisition of multispectral images in Maestro takes about 2 to 5 seconds, on average. Using DyCE (Dynamic Contrast Enhancement) technology, monochrome images can be acquired as fast as 20 Hz.

  • What is the best spatial resolution Maestro can image?

    Maestro can image from up to three whole mice down to an image with 25 microns/pixel spatial resolution. If higher resolution is required, a Nuance™ multispectral imaging system mounted on a macroscope or microscope can be used, to give resolutions down to the optical resolution limit.

  • What advantages does fluorescence have over bioluminescence?

    In vivo fluorescence measurements have several advantages over in vivo bioluminescence measurements. First, it is possible to do many more types of experiments with fluorescence. Every bioluminescence experiment has an analogous fluorescence experiment (using fluorescent proteins), but it is not possible for example to do bioluminescence experiments equivalent to determining the distribution of a protein in vivo using fluorescently labeled antibodies. Second, it is very difficult to validate in vivo bioluminescence results with ex vivo imaging, as bioluminescence is only created in living cells. Fluorescent proteins, on the other hand, can be easily imaged ex vivo to give high-resolution microscopic images of what was generating the in vivo signals (made more powerful still with the combination of Maestro and Nuance in order to maintain continuity of reported results). Lastly, the use of 'activatable' fluorescent reagents, which can turn on in the presence of particular enzymes or conditions, has no analogous experiment in bioluminescence. Fluorescence, therefore, is a more broadly based, versatile imaging modality.

  • Is your system automated?

    Yes, the Maestro 2 system is fully automated and computer-controlled.

  • How many cells or how much fluorophore do I need to have in order to image them?

    This is a very difficult question to answer, as it very much depends on the brightness of the cells and the size of the spatial location they are in. The brighter the cells/fluorophores and the smaller the location they are in, the easier it is to measure them. The smallest number of cells that have been imaged using a Maestro is 3000. [1] These were not particularly brightly labeled cells, as the detection limit for a monochrome system was 1,000,000 cells, which is considered fairly high. It is likely that for more typical brighter cells, Maestro would yield a detection limit of lower than 3000 cells.

    [1] Tam JM, Upadhyay R, Pittet MJ, Weissleder R, Mahmood U. "Improved in vivo whole-animal detection limits of green fluorescent protein-expressing tumor lines by spectral fluorescence imaging." Mol Imaging. 2007 Oct-Dec;6(4):269-76.

  • Where can I see a system?

    You can see the Maestro system at any of these events, or please contact CRi to set up a demonstration.

The CRi Maestro imaging system has many applications involving a variety of materials, such as probes, cell lines, animal specimens, etc. Certain of these applications and/or materials may require licensing under patents held by third parties. For example, a license from AntiCancer Incorporated, 7917 Ostrow St., San Diego, CA 92111 and/or Caliper Life Sciences, Inc., 68 Elm St., Hopkinton, MA 01748, may be required for certain applications and/or materials. CRi's sale or other transfer of the Maestro™ imaging system does not convey any right or license under such third party patents. It is suggested, therefore, that users of the Maestro™ imaging system consult with counsel to determine whether licensing of such third party patents is required.