YOU CAN BUILD THE 5,000-DOLLAR MACHINE THAT COUNTS CELLS, FOR 165 DOLLARS
A flow cytometry channel you can mill at home counts cells for 165 dollars instead of the usual 5,000 dollars.
by Takanobu Takenouchi, Yuta Iijima, Kazuyo Ito and Daisuke Yoshino
ScienceOpen-hardware
Built withArduino3D printing
- difficulty
- ●●●●○
- time
- a weekend-plus
- license
- CC-BY-SA-4.0
- repo
- repo FINISHED0 stars
●●●●○ · a weekend-plus · CC-BY-SA-4.0 · 0 stars · repo FINISHED
WHAT YOU’LL NEED
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COMPAREE VERDICT
This is a research-grade automated cell counter built using a CNC milled mould for PDMS microfluidics, hydrodynamic focusing, a laser diode, a photodiode and an Arduino that digitises the signal for LabVIEW on a PC, which does the peak detection and counting. The published validation against a hemocytometer on MDA-MB-231 breast cancer cells shows R² = 0.9914, which means it tracks the reference method closely. The authors are transparent: commercial Coulter counters cost up to 4,500 dollars and imager-type counters start around 5,000 dollars plus ongoing disposable slide costs; this module costs 26,692 JPY, about 165 dollars in parts. The catch is that 165 dollars covers the module only: it assumes you already have a desktop CNC mill, a vacuum chamber, an ultrasonic cleaner, an autoclave, a plasma cleaner, two syringe pumps and a LabVIEW licence, which is lab equipment, not hobby gear. The second catch is difficulty: this is not a weekend project for someone who has never done PDMS casting or built a transimpedance amplifier. The HardwareX paper is unusually complete — full protocol, dimensioned drawings, BOM with part numbers, acquisition code — but you are fabricating a working microfluidic channel and aligning optics, and the one thing most likely to go wrong is bubbles or contamination in the PDMS during casting, which will ruin the flow and force you to start over. If you are in a lab that already does microfluidics and you need an inexpensive cell counter, this is a serious option. If you are starting from zero, expect to remake the channel at least once.
IN THE REPO
GOOD TO KNOW
- —STL files for the moulds and printed parts are on Mendeley Data; the bill of materials, build protocol and data-acquisition code are in the HardwareX article and its supplementary files
- —Published as a peer-reviewed HardwareX article with full fabrication protocol
- —Licence is CC BY-SA 4.0, permits commercial use with attribution and share-alike
- —You need access to a desktop CNC mill and a vacuum chamber for PDMS degassing
- —No GitHub repository — files are hosted on Mendeley Data under DOI 10.17632/syjv86dkkk.1
- —The 165-dollar cost is parts only; it assumes you already own the CNC mill, vacuum chamber, ultrasonic cleaner, autoclave, plasma cleaner and syringe pumps.
Parts to buy
11 itemsFrom our check of the build. Exact quantities and part numbers are in the creator’s BOM.
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
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Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Read the full HardwareX article (The paper contains the complete fabrication protocol, dimensioned drawings and validation data)
- 2.Download the STL files from Mendeley Data (Nine STL files: the POM moulds for the PDMS body and holders, the beam mask and the printed window retainers. The BOM and code are in the article.)
- 3.Check you have access to a desktop CNC mill and a vacuum chamber(The 165-dollar cost assumes you already have these, plus an ultrasonic cleaner, an autoclave, a plasma cleaner and two syringe pumps; this is realistic only inside a lab.)
- 4.Order PDMS (Sylgard 184), laser diode, photodiode, op-amp components and Arduino UNO from the BOM(The BOM in the HardwareX article lists exact part numbers and Japanese suppliers (laser RP650AD5-4C, photodiode S6967, OptoSigma cylindrical lens))
- 5.Mill the mould, cast and cure the PDMS channel, assemble the optical detection module and upload the Arduino code(Follow the step-by-step protocol in the paper; expect to remake the channel at least once if this is your first PDMS casting)
KNOWN ISSUES
- The 165-dollar cost is module parts only — it assumes you already have a CNC mill, a vacuum chamber, an ultrasonic cleaner, an autoclave, a plasma cleaner and two syringe pumps, none of which are priced in the paper.
- Air bubbles or contamination in the PDMS during casting will ruin the flow channel and force you to start over; degassing in a vacuum chamber is not optional
- Aligning the laser beam, flow channel and photodiode takes patience and fine adjustments; a misaligned beam will give no signal or massive noise
- The Arduino samples at 4 kHz, so very fast flow rates may cause missed cells, and in the paper the module tended to under-count 5 µm particles compared with 15 µm ones.
- This is a research instrument validated on one cell line (MDA-MB-231); it is not a diagnostic device and has no regulatory approval for clinical use
- CC BY-SA 4.0 permits commercial use but requires you to share any modifications under the same licence
Do I need to buy a commercial cell counter to validate this?
No. The authors validated against a hemocytometer, the manual glass counting chamber that costs around 180 dollars. If your counts match a hemocytometer consistently, the module is working.
Can I use this for bacteria or yeast, or only mammalian cells?
The paper tested MDA-MB-231 breast cancer cells and 5 µm and 15 µm beads. It did detect the 5 µm beads, but tended to under-count them, so very small cells such as bacteria are not a validated use. Yeast or other small cells might work, but you would need to validate it yourself.
What if I do not have a CNC mill?
The mould could be 3D printed in resin instead of milled, but the surface finish of FDM or most resin printers is rougher than a milled surface, which may introduce defects in the PDMS channel. If you go that route, expect more trial moulds before you get a clean cast.
How long does the PDMS channel last?
The paper does not give a lifetime for the PDMS channel. The authors autoclave the module body and clean the optical windows during assembly; how long a channel lasts in your hands depends on cleaning and handling, so plan to cast spares.
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Discussion1
FROM THE COMPAREE TEAM
The published module hit R² = 0.9914 against a hemocytometer on MDA-MB-231 cells, and the authors suggest that adding fluorescence detection and sorting modules could lead to a flow cytometer for around 1,000 dollars. If you were building this, would you go straight for the sorting version, or start with the basic counter to prove the fabrication process first?
Takanobu Takenouchi, Yuta Iijima, Kazuyo Ito and Daisuke Yoshino
Published in HardwareX in 2024 by a research team developing low-cost open instrumentation for cell biology. The project is part of a broader effort to make microfluidic flow cytometry accessible to labs without access to expensive commercial equipment.
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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.
CompareeTEAM18d agoedited
Practical notes from our verification: the project is published as a peer-reviewed, open-access HardwareX article. The Mendeley Data dataset holds only nine STL files for the moulds and parts (the dataset is tagged CC BY 4.0, while the paper states CC BY-SA 4.0 for the hardware); the bill of materials with catalogue numbers, the Arduino code and the build instructions are in the article and its supplements, not on GitHub. The 165 dollars in the paper covers the module parts only. It assumes access to a desktop CNC mill for the POM moulds, a vacuum chamber for degassing PDMS, an ultrasonic cleaner, an autoclave, a plasma cleaner, two syringe pumps and a PC running LabVIEW, where the peak detection and counting happen; the Arduino only digitises the signal. The single biggest success factor is getting a clean PDMS cast, because bubbles or contamination ruin the channel and you start over. Validation used one cell line, MDA-MB-231, against a commercial hemocytometer, with R² of 0.9914, plus a sorting test separating 5 and 15 micrometre particles. 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.