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YOU CAN 3D PRINT THE BODY OF A SPECTRAL FLOW CYTOMETER FOR ABOUT 3,000 DOLLARS IN PARTS

An open spectral flow cytometer for counting and classifying cells, with fully 3D-printed mechanics and about 3,000 dollars in parts — the mechanics are done, the electronics and software are still being built.

by Samson Rogers

FULL CAD BOM FIRMWARE DOCS

ScienceOpen-hardware

Built with3D printing

difficulty
●●●●●
time
weeks-plus
license
CERN-OHL-S-2.0
repo
repo ACTIVE16 stars

WHAT YOU’LL NEED

Videos
1
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COMPAREE VERDICT

Cytkit is an open attempt to make spectral flow cytometry accessible to small and resource-limited labs. A flow cytometer pushes cells single file through a laser and reads the light each one scatters and fluoresces. Cytkit uses a single 488 nm laser with a spectral array of solid-state detectors, aiming at about 10-colour detection, for about 3,000 dollars in parts including an estimate for the planned electronics. The mechanical design is complete, fully 3D printable, and published with a supplier-level BOM under CERN-OHL-S v2. What is missing is the rest: build instructions, alignment procedures, the custom electronics and the software. Early tests with commercial photodetectors and external data acquisition already resolve 8-peak rainbow calibration beads, but the standalone instrument is not finished. If you are an optics researcher, a biohacker with lab access, or someone who wants to contribute to open lab hardware, the foundation is here. If you want to count cells next month, it is not ready.

GOOD TO KNOW

  • —FreeCAD models and STL files for the entire mechanical chassis are in the repository.
  • —Detailed bill of materials with supplier links is present, totalling about 3,000 dollars including planned electronics.
  • —CERN Open Hardware Licence v2 Strongly Reciprocal — derivative designs must stay open, and commercial use is permitted under reciprocal terms.
  • —Build, align and test documentation is explicitly still being written. The repo README states this plainly.
  • —No firmware, software or control code is published yet. Electronics integration is planned but not complete.
  • —This is a work in progress. You can print the parts and order the optics; the author has run bead tests using commercial photodetectors and external data acquisition, but the dedicated electronics and software are not released yet.

Parts to buy

6 items

From our check of the build. Exact quantities and part numbers are in the creator’s BOM.

  • 488 nm 30 mW laser diode moduleFind
  • Thorlabs lensesFind
  • Dichroic mirrorFind
  • Longpass filter and a diffraction gratingFind
  • FluidicsFind
  • Filament and screwsFind

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Can I build this?

PrintFull mechanical chassis: optical breadboard frame, detector mounts, laser housing, sample stage, fluidics manifold. Large prints; budget multi-day sessions and at least 1 kg of filament.
Buy488 nm 30 mW laser diode module, Thorlabs lenses, a dichroic mirror, a longpass filter and a diffraction grating, fluidics (micro peristaltic pump, mini diaphragm pressure pump, tubing, Luer fittings, glass capillary, filters), filament and screws. Detector and control electronics are still to come. The BOM lists suppliers; total about 2,800 dollars including the planned electronics.
ToolsFDM 3D printer, multimeter, laser safety glasses rated for 488 nm, and eventually soldering and electronics prototyping tools when the control boards are published.
SkillsAdvanced. You need optical alignment experience, fluidics troubleshooting, and comfort building scientific instruments from scratch. If you have never aligned a multi-element optical path or debugged a syringe pump, this will be extremely hard.
TimeWeeks, possibly months. Printing and parts procurement is a week. Mechanical assembly is days. Optical alignment is where the time goes — if you are experienced, days; if you are learning, weeks. Software and electronics integration will add more once those are published.
Cost$$$, dominated by the laser module, detectors and optical components. Filament and hardware are minor compared to the optics bill.
SafetyThe BOM laser is a 488 nm 30 mW module (Class 3B): direct beam or specular reflection can cause permanent eye damage. Laser safety glasses rated for 488 nm are mandatory during alignment and testing, and the author asks that you do not build it without laser safety training.

Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.

Videos

The creator's own preview of how to build Cytkit.

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Gallery

Start here

Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.

  1. 1.Read the repository README and the BOM spreadsheet in full (The README is honest about what is missing. Do not order parts until you understand the gaps.)
  2. 2.Source the laser module and detectors first(These are the long-lead and high-cost items. Verify specifications match the design before committing to the full BOM.)
  3. 3.Print the mechanical parts and do a dry-fit assembly(The STL files are in the repository. Check fit and tolerances before ordering optics.)
  4. 4.Monitor the repository for build documentation updates(Alignment procedures, control software and validation data are all still in development. Star the repo and watch for releases.)

Resources

Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.

KNOWN ISSUES

  • The build and alignment instructions do not exist yet. You will be working from CAD files and a parts list, not a step-by-step guide. If that sounds hard, it is.
  • No firmware or control software is published. The repository is mechanical design and BOM only. You cannot run this until the electronics and code are released.
  • Optical alignment is the hardest part of any flow cytometer build, and there is no procedure in the repo yet. Budget days to weeks even if you have done this before.
  • Class 3B laser hazard. If you do not already own 488 nm safety glasses and understand direct vs. specular reflection risk, learn that before you order the laser.
  • Fluidics debugging — the peristaltic sample pump, the pressurised sheath bottle, tubing, air bubbles and sample preparation — is where many DIY flow cytometer projects stall. This is not documented yet either.
  • The 3,000-dollar figure includes planned electronics. If the control board design changes or you have to prototype your own, cost and time both go up.

Can I actually count cells with this right now?

No. The mechanical design is complete and you can build the chassis, but the control electronics, firmware and alignment procedures are still in development. This is a foundation, not a working instrument yet.

What is spectral flow cytometry and why does it matter?

Traditional flow cytometers use separate detectors for each fluorescent colour. Spectral cytometry reads the full emission spectrum and unmixes it in software, which lets you detect more colours with fewer lasers and reduces spillover between channels. It is a newer, more flexible approach.

Is this actually 3,000 dollars or is there a catch?

The BOM in the repository totals about 2,800 dollars: roughly 1,200 dollars for the current optics, fluidics and hardware, plus about 1,600 dollars estimated for the electronics that are still being designed. It assumes you have a 3D printer and the skills to do integration work that is not yet documented.

Can I use this commercially?

The licence is CERN-OHL-S v2, which allows commercial use but requires that any derivative design also be published under the same licence. You cannot take this, modify it, and sell a closed product.

How does this compare to a commercial cytometer?

The project does not publish a price comparison. Cytkit is single-laser and spectral, aiming at about 10-colour detection on a 488 nm laser. It will not replace a multi-laser or sorting instrument, but it is aimed at teaching, technology development and resource-limited labs once it is complete.

Community builds

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Discussion1

FROM THE COMPAREE TEAM

The BOM comes to about 3,000 dollars and the mechanical design is complete, but the electronics and control software are still being written. If you were going to contribute to finishing this, what would you work on first: alignment procedures, electronics, or sample prep protocols?

CompareeTEAM1mo agoedited

Practical notes from our verification: the repository is refreshingly honest about where it stands. Version 0.3 contains all the mechanical parts as FreeCAD files and STLs, an optical model and a bill of materials. Still planned: the detector, data acquisition and fluidics PCBs, embedded peak-detection software and host PC software, along with complete documentation for printing, assembly, alignment and maintenance. It is not untested, though: the README says initial tests with commercial photodetectors, external data acquisition hardware and offline analysis already resolve 8-peak rainbow beads. The mechanics are fully 3D printed, so no optical table is needed. The licence is CERN-OHL-S, so derivatives must stay open. The README puts the bill of materials, including an estimate for the planned electronics, at about 3,000 dollars. If you have the optics or electronics skills to close the gaps, the foundation is solid; if you need a working cytometer today, wait for the next release. Correction (4 October 2026): we re-checked this page line by line against the project's own repository, documentation and videos, and fixed errors in earlier versions.

Samson Rogers

Samson Rogers started Cytkit to bring a low-cost open-source spectral cytometer design to the cytometry community, including resource-limited labs and teaching. The project publishes the full mechanical design, parts list and CAD files under a reciprocal open hardware licence, with build and control documentation still in active development.

GitHub

Star the project on GitHub

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  • Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
  • Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
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