alpha300 Ri - Inverted confocal Raman imaging

alpha300 Ri – Inverted Confocal Raman Imaging

Experience Raman Imaging from a new angle.


The alpha300 Ri turns 3D chemical characterization upside down. Its inverted beam path preserves all the functionality of WITec’s standard alpha300 confocal Raman imaging microscopes while introducing a new angle in access and handling. The ability to view and investigate samples from below is a great advantage when working with aqueous solutions and oversized samples. Studies in life sciences, biomedicine and geosciences in particular will benefit from the consistency and flexibility provided by the geometry of the alpha300 Ri.


Key Features

  • An inverted beam path allows liquid samples to be placed on the fixed plane of the stage for quick and repeatable measurements.
  • The motorized sample stage also facilitates the mounting of environmental enclosures and other accessories.
  • Bulky samples that would be challenging to investigate underneath a conventional microscope objective turret can be accommodated by placing them on the stage of the alpha300 Ri.
  • Compatible with other microscopy techniques including: fluorescence, differential interference contrast (DIC) and phase-contrast
  • Features all the unique and established imaging and spectroscopy capabilities of the WITec alpha300 R series.
  • Non-destructive imaging technique: no staining of fixation of the sample required


Application Examples

Correlative Raman-Fluorescence microscopy image of DAPI-marked eukaryotic cell nuclei


Correlative Raman Fluorescence Microscopy: Fluorescence DAPI Staining & Raman Imaging

3D Raman image of pressed banana pulp


The alpha300 Ri combines the advantages of data acquisition from below with the established merits of 3D confocal Raman imaging which is a powerful and versatile technique that can chemically characterize samples nondestructively and without labeling or other specialized preparation. 

The image shows a 3D reconstruction of Raman image-stack acquisition of banana pulp.

Scan range: 300µm x 200µm x 90µm
Pixels (Spectra): 450x300x45

Banana 3D Raman imaging

Pressed banana pulp sample: Starch grains (green) and cell wall components (red)


Raman General Operation Modes

  • Raman spectral imaging: Acquisition of complete hyperspectral Raman imaging data sets while continuously scanning.
  • Planar (x-y-direction) and depth scans (z-direction) with motorized sample positioning
  • Image stacks: 3D confocal Raman imaging
  • Fast and slow time series
  • Single point Raman spectrum acquisition and depth profiling
  • Fibre-coupled UHTS spectrometer specifically designed for Raman microsopy and applications with low light intensities
  • Confocal Fluorescence Microscopy


Basic Microscope Features

  • Research grade inverted optical microscope with 6x objective turret
  • Video system: Video CCD camera and/or fluorescence camera
  • LED white-light source for Köhler illumination
  • Binocular
  • Condensor lens for up to 7 contrasts (e. g. brightfield, DIC, Phase contrast, NAMC, etc.)
  • Sample holder accommodating various standard sample formats (e. g. microscopy slides, Terasakiplates, 35/65 mm dishes, counting chambers)
  • Internal filter block revolver
  • Motorized sample positioning and scanning stage in x- and y-direction, large travel range: 110 mm x 70 mm



Raman Optional/Upgradable Operation modes

  • A broad range of lasers and wavelenghts (from UV to IR) eligible
  • Additional UHTS-spectrometers (UV, VIS, NIR)
  • Ultrafast Raman imaging (1300 spectra per second) optional available
  • Upgradable for time correlated single photon counting / fluorescence lifetime imaging (FLIM)
  • Autofocus


Ultrahigh-throughput WITec UHTS Spectrometers

  • Various lens-based, excitation optimized spectrometers (UV, VIS or NIR) available, all specifically designed for Raman microsopy and applications with low light intensities
  • Fibre-coupled ultrahigh-throughput optical instruments (up to 70 % transmission)
  • Superior peak shape conservation


Computer Interface:

  • WITec software for instrument and measurement control, data evaluation and processing

Extensions & Related Instruments


  • WITec Inverted Raman Imaging System alpha300 Ri Brochure

    Open PDF
    (1.6 MB)
  • WITec alpha300 Brochure

    Open PDF
    (8.8 MB)
  • Application Note Life Science

    Open PDF
    (1.6 MB)
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