The short answer: for most UK cell-biology labs tracking live cell division, start with an inverted widefield fluorescence microscope that has a sensitive sCMOS camera, stable LED illumination and a 37 °C / 5% CO₂ on-stage incubator. The EVOS M7000 with the OSI-2 incubator is a practical plate-friendly choice for H2B-GFP or tubulin-mCherry time-lapses. If you need subcellular chromosome or spindle resolution, a spinning-disc or laser-scanning confocal is the next step. For compound screens that measure mitotic index across many wells, the CellInsight CX7 high-content platform is the better fit.
Why live mitosis imaging matters
Mitosis is the process that partitions duplicated chromosomes into two daughter cells. Errors during chromosome segregation can cause aneuploidy, genome instability and cancer progression. Watching mitosis in real time lets researchers measure:
- Timing: how long cells spend in prophase, metaphase, anaphase and cytokinesis.
- Fidelity: whether chromosomes mis-segregate, lag, or form micronuclei.
- Drug responses: how antimitotic compounds arrest or accelerate division.
- Cell-cycle transitions: the threshold of CDK1 activity that drives cells into mitosis.
Because mitosis is fast — often 1–2 hours from nuclear envelope breakdown to cytokinesis — and sensitive to temperature and pH, the microscope and environmental control matter as much as the fluorescent marker.
Microscope requirements for live mitosis imaging
| Requirement | Why it matters | Typical specification |
|---|---|---|
| Inverted optics | Cells are imaged through the base of plates or dishes. | Infinity-corrected inverted microscope |
| High NA objective | Chromosomes and spindles are small; NA controls resolution and brightness. | 40× / 0.95 NA or 60× / 1.25 NA plan-apochromat |
| Sensitive camera | H2B-GFP signals can be dim; high QE improves signal-to-noise. | sCMOS ≥65% QE or EM-CCD |
| Stable LED illumination | Long time-lapses need low photobleaching and reproducible intensity. | LED light engine with ms switching |
| Live-cell chamber | Mitosis is temperature-sensitive; cooling stalls cells in metaphase. | 37 °C, 5% CO₂ on-stage incubator |
| Time-lapse automation | Capture a field every 2–5 minutes for hours without drift. | Motorised stage, autofocus, interval acquisition |
| Fast frame rate (optional) | Short events such as anaphase onset need rapid capture. | ≥10 frames per second for full-field bursts |
Widefield vs confocal vs high-content for mitosis
| Approach | Best for | Strengths | Limitations |
|---|---|---|---|
| Widefield inverted fluorescence (EVOS M7000, EVOS M5000) | 2D monolayers, H2B-GFP time-lapse, multiwell plate surveys | Fast, gentle, easy to use, plate-friendly, lower cost | Out-of-focus blur in thick samples; limited sub-micron detail |
| Spinning-disc / laser-scanning confocal | Spindle dynamics, chromosome congression, thick organoids, FRAP/FRET | Optical sectioning, low background, subcellular resolution | Higher cost, more photobleaching, slower for large fields |
| High-content screening (CellInsight CX5/CX7) | Mitotic index screens, compound dose-response, plate statistics | Automated multiwell acquisition, built-in mitotic classifiers | Lower frame rate than dedicated live-cell systems; higher investment |
EVOS M7000 for live mitosis time-lapse
The EVOS M7000 is a fully automated, inverted LED fluorescence microscope that fits many live-mitosis workflows in UK labs:
- OSI-2 on-stage incubator — maintains 37 °C and 5% CO₂ for overnight or day-long movies.
- GFP + RFP channels — image H2B-GFP chromosomes together with tubulin-mCherry or SiR-tubulin spindles.
- Multiwell plate compatibility — run 96-well compound treatments and image the same positions automatically.
- Z-stacking — capture dividing cells across the full nuclear depth.
- Time-lapse scheduling — acquire images every few minutes for many hours.
For straightforward “where is mitosis arresting?” or “how long is metaphase?” experiments, EVOS M7000 is usually enough. If your question is about kinetochore–microtubule attachment geometry, upgrade to a confocal.
CellInsight CX7 for high-content mitotic screens
If your experiment asks “which compound changes the mitotic index across a whole plate?”, a high-content system wins. The CellInsight CX7 High-Content Analysis Platform combines fluorescence microscopy with automated classification:
- Plate-level acquisition with autofocus and laser autofocus for reproducible focus.
- Integrated cell-cycle and mitotic-index algorithms based on DNA and phospho-histone H3 staining.
- Multiplexing with tubulin, centromere or kinetochore markers for phenotypic detail.
- Exportable dose-response curves for antimitotic compounds.
The CX7 is not the tool for filming single-cell anaphase in real time at high frame rate, but it is the right platform for statistical mitotic phenotyping.
Fluorescent markers and biosensors for mitosis
| Marker | What it shows | Imaging notes |
|---|---|---|
| H2B-GFP / H2B-mCherry | Chromosome position and nuclear envelope breakdown | Best general-purpose reporter for mitosis tracking; use low expression to avoid toxicity. |
| Tubulin-GFP / SiR-tubulin | Spindle morphology and dynamics | SiR-tubulin is far-red and dye-based, useful in non-transgenic cells. |
| Cyclin B1-GFP | Degradation timing at anaphase onset | Reports the biochemical exit from mitosis. |
| FRET biosensors for CDK1 or PLK1 | Kinase activity thresholds during mitotic entry | Requires ratiometric imaging; best on confocal or spinning-disc systems. |
| Phospho-histone H3 | Mitotic cells in fixed or HCS assays | Endpoint assay; not suitable for live-cell movies. |
Practical tips for filming mitosis in UK labs
- Use a thin cell line and sparse plating — overlapping cells make tracking chromosomes harder.
- Pre-warm everything — media, stage, objectives and chamber. A 1 °C drop can lengthen metaphase.
- Keep exposures short — 50–200 ms per frame is typical for H2B-GFP. Longer exposures bleach the marker.
- Capture every 2–5 minutes — enough to catch nuclear envelope breakdown, metaphase, anaphase and cytokinesis.
- Use autofocus cautiously — laser autofocus can cause phototoxicity in sensitive lines; software drift correction is gentler.
- Normalise to cell count — report mitotic index as a percentage of total nuclei, not raw counts.
Recent publications and resources
Live Cell Imaging of Chromosome Segregation During Mitosis
Vara et al., J Vis Exp, 2018. doi: 10.3791/57389.
A visual protocol for long-term live-cell imaging of chromosome segregation in cultured mammalian cells.
DOI: 10.3791/57389Live Cell Fluorescence Imaging for Phenotypic Analysis of Mitosis
Sampson et al., Methods Mol Biol, 2014. doi: 10.1007/978-1-4939-0888-2_31.
Methods for using fluorescent biosensors and reporters to phenotype mitotic progression.
DOI: 10.1007/978-1-4939-0888-2_31Using Fluorescence Microscopy to Study Mitosis
DeLuca & McGorty, Methods Mol Biol, 2016. doi: 10.1007/978-1-4939-3542-0_1.
Practical guide to fluorescence microscopy techniques for mitosis research, including fixed and live methods.
DOI: 10.1007/978-1-4939-3542-0_1Live-cell Imaging Defines a Threshold in CDK Activity at the G2/M Transition
Aoki et al., Dev Cell, 2023. doi: 10.1016/j.devcel.2023.05.003.
Demonstrates how live-cell imaging and FRET biosensors can map the timing of mitotic entry.
DOI: 10.1016/j.devcel.2023.05.003FRET-Based Sorting of Live Cells Reveals Shifted PLK1/CDK1 Balance
Gavet et al., Cells, 2020. doi: 10.3390/cells9092126.
Shows how FRET biosensors for mitotic kinases can be combined with fluorescence microscopy to study checkpoint recovery.
DOI: 10.3390/cells9092126EVOS M7000 Imaging System — UK
Thermo Fisher Scientific UK product page.
Specifications, OSI-2 incubator options and ordering information for UK labs.
thermofisher.com/uk/evos-m7000Frequently asked questions
What microscope do I need to image mitosis in live cells?
For routine long-term tracking of mitosis in 2D monolayers, an inverted widefield fluorescence microscope with a sensitive camera, stable LED illumination and a 37 °C / 5% CO₂ on-stage incubator is enough. For subcellular chromosome dynamics, optical sectioning, or FRAP/FRET, use a spinning-disc or laser-scanning confocal. For plate-level mitotic index screens, use a high-content system such as CellInsight CX7.
Can I use an EVOS M7000 for live mitosis imaging?
Yes. EVOS M7000 with the OSI-2 on-stage incubator is well suited for hours-long time-lapse of live cell division in multiwell plates or dishes. It supports GFP/RFP channels, automated multi-point acquisition and Z-stacking, which are ideal for H2B-GFP or tubulin-mCherry mitosis movies. It is a widefield system, so very fine chromosome congression details may be better resolved on a confocal.
What fluorescent markers are best for visualising mitosis?
Histone H2B-GFP or H2B-mCherry labels chromosomes and is the standard reporter for tracking nuclear envelope breakdown, chromosome alignment and segregation. Tubulin-GFP or SiR-tubulin reveals spindle dynamics. FRET biosensors for CDK1 or PLK1 activity report the biochemical timing of mitotic entry and exit. For flux measurements of cyclin B1, use a cyclin B1-GFP degradation reporter.
Do I need confocal microscopy for mitosis imaging?
Not always. Widefield microscopy is sufficient for whole-cell mitosis tracking with H2B-GFP in monolayers. Confocal or spinning-disc confocal improves resolution of kinetochore dynamics, spindle microtubules, thick samples, and reduces out-of-focus blur. Choose confocal when you need optical sectioning or sub-micron spatial precision.
How do I analyse mitotic movies automatically?
Free tools include Fiji / ImageJ with TrackMate or the Cell Tracking Challenge pipelines, and CellProfiler for mitotic index counting. Commercial options include Imaris, Volocity and arivis for tracking division trajectories. High-content systems such as CellInsight CX7 have built-in mitotic index and cell-cycle-phase classification algorithms.
Where can I do advanced live mitosis imaging in the UK?
Most UK university bioimaging core facilities have spinning-disc confocals and environmental chambers suitable for live mitosis imaging. Regional cores include the York Imaging Facility, Francis Crick Light Microscopy, MRC Laboratory of Molecular Biology, Nikon Imaging Centre at King's College London, and Edinburgh Super-Resolution Imaging Consortium. For high-throughput mitotic screens, Cambridge and Oxford CROs offer CellInsight HCA services.