These are some considerations and guidance to help you determine the best instrument for your application, but it’s certainly no substitute for a quick visit to our facility to speak with us directly (which we welcome!). Biosafety level, environmental needs, resolution performance, sources, detectors, geometry, stage and experimental control are all important considerations when selecting the best instrument. You will need a microscope that is:

1. Compatible with the biosafety level of your sample:
   1. Leica SP8 confocal microscope is the only microscope currently approved for use with BL-2 samples
2. Maintains an appropriate environment for your sample:
   1. Leica SP8 and Olympus FV1000 confocal microscopes have controllable environmental chambers for live cell imaging at 38°C and 5% CO₂.
   2. Zeiss Z.1 Light Sheet operates at 30°C which is suitable for live imaging of zebrafish embryos.
3. Sufficient resolution capabilities to capture the details you want to see:
   1. In order from highest to lowest resolution performance (axial resolution):
      • Leica SP8 (STED mode, confocal) > Olympus FV1000 (confocal) > Leica DM 6B (widefield) > Zeiss Axiophot (widefield).
   2. Leica SP8 in superresolution STED mode offers down to ~40nm lateral resolution.
   3. Leica SP8 can perform deconvolution to improve resolution.
   4. The microscopes all have comparable lateral resolution, depending on the numerical aperture of the objective used.
4. Has the desired Imaging/Contrast mode:
   1. Fluorescence is available on the Leica SP8 confocal, Olympus FV1000 confocal, and Leica DM6B confocal.
   2. Leica DM6B and Zeiss Axiophot offer Phase Contrast with most objectives.
   3. Leica DM6B and Zeiss Axiophot allow Polarized Light imaging in transmitted light. Zeiss Axiophot is the only instrument to offer reflected light, polarized light microscopy, and allows for stage rotation. The Axiophot has compensator plates (1 lambda and ¼ lambda ) for polarized light imaging.
   4. Reflected light DIC is only available on Zeiss Axiophot.
   5. FLIM (Fluorescence Lifetime Imaging Microscopy) is available on the Leica SP8 confocal.
5. Sources suitable for your samples:
   1. Leica SP8 confocal, Olympus FV1000 confocal, and Zeiss Z.1 Light Sheet have lasers that cover the visible spectrum suitable for imaging most fluorophores.
   2. The Leica SP8 confocal has a 440nm pulsed laser (good for FLIM/FRET). It also has a white light laser for adjusting excitation to peaks of fluorophores that are away from the common laser lines.
   3. The Olympus FV1000 has two 405 lasers on separate scanners for FRAP/confocal imaging.
   4. The Leica DM6B has a white LED source with a variety of filters. The Leica SP8 and Olympus FV1000 also have low power, white light sources for widefield fluorescence observation/screening.
   5. All of the optical microscopes can image transmitted light and are capable of DIC with most of the objectives.
6. Detectors are sensitive and fast enough to capture weak signals, dynamic processes, or large volumes:
   1. The Leica SP8 confocal has HyD hybrid point detectors that can be gated to reduce background from reflections and fast lifetime autofluorescence.
   2. The Leica SP8 can work in resonant scanning mode for fast imaging (>30fps at 512 x 512 pixels).
   3. The Zeiss Z.1 images entire planes at once (rather than point-scanning) for fast volumetric imaging.
7. Geometry that works:
   1. The Leica SP8 confocal and Olympus FV1000 confocal are inverted.
   2. The Leica DM6B and Zeiss Axiophot are upright.
   3. The Zeiss Z.1 Light Sheet has orthogonal illumination and detection paths.
8. Stage control for automated acquisition and image stitching:
   1. The Leica SP8 confocal can automatically collect volumetric tiles over large fields of view and stitch them together.
   2. The Leica DM6B can automatically collect tiles over large fields of view and stitch them together.
   3. The Olympus FV1000 can automatically collect tiles, but stitching must be done elsewhere.
   4. The Zeiss Z.1 Light Sheet can automatically collect volumetric tiles, but stitching must be performed elsewhere.