Q-PHASE: Quantitative label-free imaging cytometry

Quantitative phase imaging (QPI) is a novel label-free imaging technique bringing a completely new contrast into the live cell imaging field. It allows extracting information-rich quantitative data from unlabelled cells. It is directly proportional to the cellular dry mass and can be used for monitoring and direct quantification of dry mass changes inside the cells in pg/μm². Thanks to the high sensitivity, even the slightest mass changes can be detected and quantified. Q-PHASE uses a patented technology of coherence-controlled holographic microscopy to provide QPI of the highest quality. Additional imaging modalities are available such as widefield fluorescence, simulated DIC, brightfield or high-pass filtered QPI. Multiple dimensions can be combined in a single experiment and automatically acquired by the Q-PHASE system (timelapse, multi-position, multi-channel, Z-stack). The system is optimized for long-term several-day experiments with living cells.

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Unique cellular contrast

The quantitative phase imaging directly visualizes cellular mass (thickness × refractive index).

Transparent cells made visible

Even the most transparent cells and their parts can be distinguished from the background.

Look inside the cells

Changes in internal parts of cells such as nuclei, vacuoles, and many more, can be seen without any labelling.

Multiple imaging modes

Additional modalities can be collected simultaneously to provide a more complete picture in a synergistic fashion.

QPI images offer the highest cell/background contrast among other label-free imaging techniques thus enabling the most reliable and precise automatic segmentation of individual cells. Even highly confluent populations can be reliably segmented. Moreover, fluorescence data can be utilized to refine the segmentation even further. QPI-based segmentation is also very fast, which significantly speeds up analyses of large datasets with thousands of frames.

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The powerful Q-PHASE analysis toolbox processes segmented images on-the-fly and provides a complex portfolio of tools for data visualization, subpopulation gating and multi-parameter data mining. It links quantitative data to images and individual cells, which makes optimizing gates and checking outliers extremely easy and efficient. Resulting data can be exported in common file formats for further processing and analysis.

Simple automated image segmentation and processing – reliable and fast, comparable to fluorescence data processing
No image artifacts such as halo effect (as opposed to techniques based on Zernike phase contrast illumination)
Very precise detection of cell boundaries
Label-free – no staining is needed, simple sample preparation, observation of live cells in their native environment, no photobleaching problems
Low phototoxicity – low light power density (10⁷× lower than fluorescence microscopy) allows long-term observations (for days)
Coherence-gating effect – Q-PHASE special feature enabling to observe samples even in scattering media (phospholipid emulsions, extracellular matrices, etc.)
Multimodality – fully integrated fluorescence module, simulated DIC, brightfield and high-pass filtered QPI
High-quality QPI – Q-PHASE’s unique optical setup allows using incoherent illumination which provides extraordinary imaging quality without any compromises

Strong suppression of coherent noise (speckles) & parasitic interferences (as opposed to laser-based approaches)
Lateral resolution of conventional microscopes (up to 2× better when compared to common laser-based approaches or pinhole spatial filtering based techniques)
Fast acquisition – the use of off-axis holographic approach makes Q-PHASE a single-shot instrument, thus enabling imaging of very fast cell dynamics
Full motorization – focusing, sample stage, objective exchange, fluorescence filters
Automated multidimensional acquisition – time-lapse, channel, position, Z-stack
Quantitative – phase values can be recalculated e.g. to cell dry-mass density (pg/μm²) or direct topography with nanometer sensitivity (typically non-biological samples with homogeneous refractive index distribution)
High phase detection sensitivity – enables to detect even the smallest changes in axial direction, very sensitive detection of morphology or position changes