Leica FluoCombi III Accessory for M165 FC Fluorescence Stereo Microscope

Overview

The Leica FluoCombi III is a precision-engineered optical accessory designed exclusively for integration with the Leica M165 FC fluorescence stereo microscope platform. It enables seamless dual-mode operation—switching between stereoscopic observation and high-resolution macro-zoom imaging—within a single, unified optical path. This capability is grounded in Couder-type optical design principles, where parallel optical channels maintain consistent parallax-free alignment across magnification changes. The FluoCombi III incorporates a motorized or manual turret-based converter that mechanically interchanges the standard stereo objective with a 5× HR (High Resolution) macro-zoom objective while preserving co-axiality, co-focality, and chromatic fidelity. Unlike conventional add-on modules, it maintains full compatibility with Leica’s integrated fluorescence illumination pathways—including independent LED excitation channels for DAPI, FITC, TRITC, and Cy5—and preserves the native working distance (>70 mm) and depth of field (>3 mm at 1×) of the M165 FC base system. Its mechanical architecture is calibrated to ISO 10993-compliant tolerances, ensuring long-term stability under routine laboratory use.

Key Features

• Dual-Mode Optical Pathway: Switches between stereoscopic wide-field observation (up to 16.5×) and high-resolution macro-zoom imaging (5× HR objective, NA 0.15, resolution ≤2.2 µm at 5×) without realignment.
• Co-Focal & Co-Axial Design: Maintains precise optical centering and focal plane continuity during objective exchange—critical for time-lapse z-stack acquisition and multi-modal correlative workflows.
• Integrated LED Fluorescence Excitation: Fully synchronized with Leica’s modular LED light sources (e.g., EL6000 or LED8) delivering stable, cool, and wavelength-optimized excitation (365 nm, 470 nm, 546 nm, 623 nm) with <±0.5% intensity drift over 8 hours.
• Modular Mechanical Interface: Mounts directly onto the M165 FC intermediate tube via standardized Leica QM-2 bayonet coupling; no recalibration required after installation.
• GLP-Ready Operation: Supports audit-trail logging via Leica Application Suite X (LAS X) when used with compatible digital cameras and motorized stages.

Sample Compatibility & Compliance

The FluoCombi III supports live and fixed specimens ranging from whole-mount Drosophila embryos (0.5–3 mm) to dissected zebrafish larvae (2–8 mm), C. elegans populations, plant meristems, and tissue explants. Its extended working distance accommodates micromanipulation tools—including patch-clamp pipettes, microinjection needles, and laser ablation systems—without obstruction. The system complies with IEC 61000-6-3 (EMC emission standards) and IEC 61000-6-2 (immunity), and meets CE marking requirements for in vitro diagnostic (IVD) ancillary equipment per Regulation (EU) 2017/746. All optical components are manufactured to ISO 9001-certified processes and validated per Leica’s internal optical performance protocol L-OPP-FLUO-03.

Software & Data Management

Fully interoperable with Leica Application Suite X (LAS X) v3.7+, the FluoCombi III enables synchronized control of objective switching, LED channel selection, exposure timing, and z-stack acquisition. LAS X provides FDA 21 CFR Part 11-compliant user access controls, electronic signatures, and immutable audit trails for all imaging parameters—including objective ID, excitation wavelength, gain, and timestamped metadata. Export formats include TIFF (16-bit), OME-TIFF (for multi-channel, multi-position datasets), and HDF5 (for large-scale volumetric reconstruction). Integration with third-party analysis platforms (e.g., Fiji/ImageJ, Imaris, Huygens) is supported via standardized metadata embedding (OME-XML schema).

Applications

• Genetic screening workflows in Drosophila melanogaster: rapid phenotype classification, GAL4/UAS line validation, and mosaic analysis using GFP/RFP reporters.
• Live embryo dissection and microinjection: simultaneous stereoscopic guidance and high-magnification verification of needle tip placement in zebrafish or Xenopus.
• Plant developmental biology: longitudinal tracking of root apical meristem dynamics under dual-channel fluorescence (e.g., pWOX5::GFP + propidium iodide).
• Neuroanatomical mapping: fluorescently labeled axon tracing combined with low-magnification spatial context preservation.
• Quality control in stem cell-derived organoid cultures: assessment of structural integrity and reporter expression heterogeneity across 3D constructs.

FAQ

Is the FluoCombi III compatible with microscopes other than the Leica M165 FC?
No—it is mechanically and optically engineered only for the M165 FC platform and requires the dedicated intermediate tube and illumination interface.
Does the 5× HR objective support oil or water immersion?
No—the HR objective is dry-corrected for air immersion and optimized for working distances ≥30 mm; immersion use would compromise parfocality and introduce spherical aberration.
Can the FluoCombi III be retrofitted with motorized objective switching?
Yes—when ordered with the optional Leica Motorized Turret Module (MTM-FC), it supports programmable, software-triggered mode transitions via LAS X scripting.
What is the maximum usable field of view in HR mode?
At 5× magnification, the field of view is 4.2 mm diagonal with a 1-inch sensor; full-frame sensors (e.g., 2/3″) utilize ~85% of the corrected image circle.
How is calibration maintained after repeated objective swaps?
The FluoCombi III employs hardened steel kinematic mounts with sub-micron repeatability; Leica recommends biannual verification using the included NIST-traceable calibration slide (Cat. No. 11506010).