'We offer a step by step description of how to make a battery powered 9-24 volt DC motor driven centrifuge for separation of cell in fluid suspension for under 20 dollars. This centrifuge may be used in the field (when no other technology is available), and is set in a cookie tin or coffee can to prevent accidental release of content.
Bullet shells act as the "buckets" for the centrifuge.
Paperclips are bent to hold the shell casings, which spin out when the motor begins to turn.
A DC motor speed controller allows control over acceleration and deceleration.
A motor spinning at 2000-2500 RPM with a radius of 2 inches will develop the
600 g of centrifugal force required to separate cells in fluid suspension.
We used 1 milliliter pipettes which fit into the bullet casings to spin-down a "cell pellet"
in a pleural fluid sample however a "virtual tube" of cellophane will also work .
This project was supported in part by the Center for Parabiotics Research.
Project team members: R Siderits, J Jaworski, W Lecorchick, O Ouattara
Step 1: Finished prototype
Here is an image of the completed centrifuge. We chose to place the motor, arms, and buckets on the outside of this cookie tin for demonstration purposes. You may choose a larger coffee tin or better yet, a 12" diameter, 2-3 inch deep cookie tin to place it inside.
Use the lid of the cookie tin to completely cover the centrifuge for safety.
The knob on the front of this image is the DC motor control. We used a two part plastic and a bottle cap as a mold for both the rotor head (center) and the speed controller knob.