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+ | <p>In our automated system, a crucial step is to extract DNA in order to get through our detection process. Indeed at the end of the lysis step, our solution contains a lot of cellular debris that could prevent the process from being carried out correctly.</p><p> | ||
+ | A lot of different methods can be used to purify DNA in a lab. The most common example is the use of a silica minicolumn DNA purification. </p> | ||
+ | Looking at all those purifications methods from an engineering point of view, the main common issue is the need for a centrifugation step at some point in the process. As it is difficult to obtain the necessary force to extract DNA in a small low-cost automated system, we looked for an alternative way and that’s how we discovered about magnetic beads. </p> | ||
+ | <br> | ||
+ | <figure><center><img src="https://static.igem.org/mediawiki/2018/3/35/T--Grenoble-Alpes--purifFig1.png"><figcaption>Figure 1: Schematics of a magnetic bead </figcaption></center></figure> | ||
+ | <br> | ||
+ | <p>Magnetic beads are very small (1 µm) particles, consisting of a ferromagnetic core and a coating.</p><p> | ||
+ | The coating of the beads is used to attach the DNA in the solution, whereas the ferromagnetic core is used to move the beads to the edge of the tube. It allows us to extract DNA by applying a magnetic field following by a few washing steps.</p> | ||
+ | <p>In order to apply the magnetic field, we used small permanent magnets and an actuator. The magnets are crimped in a 3D printed part, which is fixed to the motor. Thanks to this system we can place the magnets closer or further away from the tubes, allowing us with the pipette to automate the DNA extraction.</p> | ||
+ | <br> | ||
+ | <figure><center><img src="https://static.igem.org/mediawiki/2018/f/f7/T--Grenoble-Alpes--fluofig3.png"><figcaption>Figure 2: Schematics of a magnetic bead </figcaption></center></figure> | ||
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+ | Click on the button below to get more details about how magnetic beads work, and the different washing steps of a DNA extraction using them. | ||
Revision as of 14:21, 14 October 2018
Template loop detected: Template:Grenoble-Alpes
PURIFICATION MODULE
In our automated system, a crucial step is to extract DNA in order to get through our detection process. Indeed at the end of the lysis step, our solution contains a lot of cellular debris that could prevent the process from being carried out correctly.
A lot of different methods can be used to purify DNA in a lab. The most common example is the use of a silica minicolumn DNA purification.
Looking at all those purifications methods from an engineering point of view, the main common issue is the need for a centrifugation step at some point in the process. As it is difficult to obtain the necessary force to extract DNA in a small low-cost automated system, we looked for an alternative way and that’s how we discovered about magnetic beads.Magnetic beads are very small (1 µm) particles, consisting of a ferromagnetic core and a coating.
The coating of the beads is used to attach the DNA in the solution, whereas the ferromagnetic core is used to move the beads to the edge of the tube. It allows us to extract DNA by applying a magnetic field following by a few washing steps.
In order to apply the magnetic field, we used small permanent magnets and an actuator. The magnets are crimped in a 3D printed part, which is fixed to the motor. Thanks to this system we can place the magnets closer or further away from the tubes, allowing us with the pipette to automate the DNA extraction.
Click on the button below to get more details about how magnetic beads work, and the different washing steps of a DNA extraction using them.