Figure 1. Model outline of FlyPi (left) and the assembled microscope system (right).
At the current exchange
Note: Left: A 3-D model of FlyPi. Right: FlyPi with
In March 2017 Andre Maia Chagas published an article in bioRxiv  entitled, ‘The 100 € lab: A 3-D printable open source platform for fluorescence microscopy, optogenetics and accurate temperature control during behaviour of zebrafish, Drosophila and C.
The plans for the project have been online since 2015 and their objective was simple – to develop a complete open source microscopy-based device for scientific experiments and diagnostics. Furthermore, it needed to be affordable and adaptable to enable users to tailor their set-up to meet their research objectives.
The basic set-up
Figure 2 shows the basic components of FlyPi. These include:
- The 3-D printed framework (see Figure 1) printed in polylactic acid on an Ultimaker 2 3-D printer. It took around 40 hours to print the framework.
- A Raspberry Pi computer that runs Raspian.
- A Raspberry Pi camera with mounted objective (lens) plus some python3 code so the graphical user interface can be customised and recorded data can be saved.
- An Arduino – an open-source microcontroller.
- A custom printed circuit board and additional parts to coordinate outputs (i.e. the timing of lighting and heating) and inputs (temperature sensing).
Figure 2. FlyPi components.
The above components are the building blocks of FlyPi and it is a system that is low cost and that can be modularised. However, the authors had to demonstrate that the system worked in the laboratory. This was done using fluorescence imaging in live animals and included:
- Calcium dynamics. Data were recorded in transgenic zebrafish larva that express the green fluorescent protein-based calcium sensor GCaMP5G and permitted the imaging of their heart calcium dynamics. Moreover, larval Drosophila were allowed to crawl on a microscope slide and these video recordings revealed clear calcium signals that were associated with the peristaltic movements of the
- Behavioural tracking. The colour camera was also used to video-monitor the movement of adult Drosophila in a petri dish.
- Optogenetics. In zebrafish larva expressing ChR2, FlyPi’s LED ring (Figure 2) was used to stimulate, using blue LEDs, pectoral fin swimming bouts which were accurately captured using the test set-up. And, in Drosophila larvae expressing CsChrimson in the gustatory circuit, FlyPi was also able to capture the proboscis extension reflex upon following activation with red LEDs.
- Thermogenetics. Accurate control of temperature also means that FlyPi can be used to selectively activate or well neuronal synapses.
Andre Maia Chagas and his co-workers make it clear that the current version of FlyPi is “…only scratches the surface of possible applications” . Indeed, there are some easy developments that would rapidly improvement the system, the obvious one being better spatial resolution which currently can visualise human red blood cells but not smaller bodies such as malaria parasites. Other suggested improvements include auto-focusing and wireless networking. No doubt all these improvements will eventually make it into future versions of FlyPi. It’s worth remembering that the current system was intended to be cheap, to be modular and to be available through open-source platforms. The current project has also delivered an accessible research, training and educational tool as well as opening-up new avenues in medical and disease diagnosis.
 ANDRE MAIA CHAGAS, LUCIA PRIETO GODINO, ARISTIDES B.
ARRENBERG, TOM BADEN. THE 100 € LAB: A 3-D PRINTABLE OPEN SOURCE PLATFORM FOR FLUORESCENCE MICROSCOPY, OPTOGENETICS AND ACCURATE TEMPERATURE CONTROL DURING BEHAVIOUR OF ZEBRAFISH, DROSOPHILA AND C. ELEGANS. BIORXIV 2017. SOURCE: HTTP://DX.DOI.ORG/10.1101/122812.
 3-D PRINT YOUR OWN LAB EQUIPMENT. SOURCE: HTTPS://OPEN-LABWARE.NET/PROJECTS/FLYPI/
 CODE REPOSITORY FOR FLYP.
Speak to the Applications team at MCI to discuss other creative ways to save money when doing high-end imaging and electrophysiology.