How a motorized filter cube turret expands microscope performance across advanced imaging workflows

A motorized filter cube turret – like our new HF108FC wide field filter turret is sometimes seen as a convenient add-on, but in advanced microscopy, it plays a far more important role whether for upgrading existing equipment or as a vital component in OEM systems.

A filter turret is a rotating carousel that holds multiple fluorescence filter cubes, each containing excitation, dichroic, and emission filters. It’s housed inside the body of the microscope, which gives excellent alignment stability and mechanical repeatability.

By enabling quick, consistent, software-driven switching between excitation, dichroic, and emission filter sets, it boosts imaging speed, consistency, and flexibility. This capability is especially valuable in complex microscopy techniques such as fluorescence recovery after photobleaching (FRAP), fluorescence lifetime imaging microscopy (FLIM), fluorescence in situ hybridization (FISH), confocal, super-resolution, and multiphoton imaging, where precise timing, spectral accuracy, and automation can directly influence the results.

The true value of a motorized turret comes from three features: 

• precise positioning, 
• rapid switching, 
• seamless integration with imaging software. 

Manually changing filters can disrupt workflows, cause alignment issues, complicate synchronized experiments, and slow down multi-wavelength imaging. With a motorized system, these challenges are minimized—the microscope can switch to the appropriate optical path for each imaging mode or fluorophore within milliseconds, with minimal input from the user.

Why motorization matters

Imaging labs rarely use microscopes for just one task. Modern systems are often expected to capture multichannel images, handle live-cell time-lapse experiments, perform photomanipulation, and then switch to different sample types or contrast methods. A motorized filter cube turret makes these transitions easier by:

• reducing handling and operator error
• enabling scripted multichannel imaging
• improving repeatability between experiments and users
• shortening acquisition time in live or dynamic studies
• supporting unattended or high-content imaging workflows.

These benefits are broadly useful for all fluorescence microscopy, but they become especially significant in specialized imaging modalities.

Caption: Prior Scientific’s 8-position motorized high-speed filter turret, HF108FC

Operational Benefits Beyond Image Quality 

The benefits of a motorized turret go beyond simply improving image quality; they make day-to-day operation easier. It supports: 

• Automation: essential for time-lapse, tiled imaging, and screening 
• Reproducibility: same optical settings every run 
• Throughput: faster channel changes and reduced setup time 
• Sample protection: less exposure caused by slower manual workflows 
• User friendliness: easier operation for multi-user labs and core facilities.

The automation sets up the microscope for future upgrades. As experiments get more complex and software-driven, motorized optical components shift from being extras to essential parts of the system. 

Optimizing automated fluorescence microscopy with high-speed filter switching

Automated filter switching increases precision in basic fluorescence imaging. Using a high-quality filter turret minimizes pixel shifts (small spatial misalignments between images of the same field of view acquired in different fluorescence channels), which improves the image quality by eliminating unwanted effects such as color fringing or false offsets. 

A motorized filter turret enables users to improve signal-to-noise in automated multichannel imaging by using dedicated single-band filter cubes for each fluorophore. This reduces background bleed-through that can occur with multiband cubes often used in semi-motorized systems or with external filter wheels. 

Filter turrets with a large number of positions can enable multiplexing experiments in which some channels will be weak. These weak channels will benefit from having a single dedicated cube with a long-pass emission filter. A high-speed filter wheel such as Prior’s HF108B to house single band emission filters, combined with a turret fitted with a series of dual or triple band filters with large spaces between the bands, is also a good alternative when imaging at very high speed is also a consideration. A motorized filter cube turret makes it easy for users to find and frame the correct field of view (FOV) by switching into a widefield overview configuration before performing any high-end imaging. This reduces the risk of photobleaching in delicate samples, as the widefield overview allows users to quickly locate the right region with a lower illumination dose than searching in a high-intensity illumination mode, such as confocal or FRAP.

FISH: Efficient Multicolor Imaging for Cytogenetics and Spatial Biology 

Fluorescence in situ hybridization (FISH) often requires imaging several spectrally distinct probes on the same sample. Whether the application is clinical cytogenetics, cancer pathology, or spatial genomics, success depends on clean channel separation and efficient multicolor acquisition. 

A motorized filter cube turret is especially useful in these cases because it enables fast switching between probe-specific filter sets without disturbing the sample or shifting the field of view. This boosts productivity and reduces the risk of misalignment caused by manual handling. In automated scanning, the turret lets the microscope move through channels in a consistent sequence—essential for reliable stitching, analysis, and reporting. 

Users often need to switch between multiple filter cubes for each image when using FISH. There may be thousands of cube changes per tissue specimen. A durable, robust filter turret is essential for long-term, consistent performance. 

For higher-plex applications, combining a filter turret with multiple single and dual-band filter cubes can allow the number of channels imaged to exceed the number of positions in the turret without compromising on bleed-through or resorting to spectral unmixing.

Reflected Light Imaging for Industrial Samples

Imaging industrial samples often requires a combination of techniques, and a filter turret enables rapid switching between filter cubes for different modalities. 

Caption: Examples of a polarizing (right) and darkfield (left) filter cube.

In addition to brightfield, darkfield, and polarized light microscopy for defect detection or inspection, some industrial applications also use fluorescence microscopy to detect biological material on the sample. All of these imaging modalities require specific arrangements of optics, which are housed inside a turret. Typically, industrial imaging systems are manual – a motorized turret can greatly increase the rate of inspection and allow multiple types of defects to be detected without the intervention of the user or repeated investigation. 

Laser ablation uses a high-intensity laser beam to remove material from a surface, and may be included as part of an inspection workflow to prepare the sample. In particular lasers or other high-intensity light sources can be used to mark or knock out components of semiconductor wafers during inspection. A specific filter cube is often necessary to protect the camera sensor. A filter turret that allows optics to be changed and refitted, rather than one with a fixed design, allows the optics to be configured to the wavelength and power of the light source being used.

As with FISH, the ability to switch rapidly between many filters improves industrial imaging workflows. 

Take your microscopy further 

For labs doing more than simple single-channel imaging, a motorized filter cube turret is much more than a convenience: it’s a practical upgrade that boosts reproducibility, enables automation, and expands the microscope’s capabilities for advanced imaging. 

The HF108FC from Prior Scientific offers users a fast 200 ms switching time (25% faster than competing products), combined with accurate and repeatable stepper motor control, to ensure maximum efficiency in complex imaging workflows. It is a robust option, proven in testing to 20 million cycles, which equates to around half a million hours of typical lab use. Designed for use with Prior’s modular OpenStand imaging system or as a standalone unit inside an OEM instrumentthe turret is suitable for upright or inverted microscopy. 

Contact us to learn more.