Inverted Confocal Raman Imaging

alpha300 Ri from WITec

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.

  • Consistent, repeatable positioning of liquid samples
  • Motorized sample stage
  • Easy Bulky samples analysis
  • Features all imaging and spectroscopy capabilities of the WITec alpha300 R series, included its modularity and expandability
  • Non-destructive, contact-free, label-free chemical characterization
  • True confocality, ideally suited to 3D image generation
  • Lateral resolution limited only by physical law
  • Compatible with other microscopy techniques (fluorescence, DIC, phase-contrast, …)

Further information

An inverted beam path allows liquid samples to be placed on the fixed plane of the stage for quick and repeatable measurements.

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.

The motorized sample stage also facilitates the mounting of environmental enclosures and other accessories.

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

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 microscopy 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, Nunc flasks, counting chambers)
  • Internal filter block revolver
  • Motorized sample positioning and scanning stage in x- and y-direction, large travel range

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 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
  • Superior peak shape conservation

Computer Interface:

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


alpha300Ri Brochure
Application Note - Life Sciences


Stephane Struyve
Stephane Struyve

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Quantum Design GmbH

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Phone+32 230 84324
Mobil:+32 495 797175
Stephane StruyveSales Manager
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