ASSIST PLUS: Magnetic Bead Purification automated with the ASSIST PLUS (video)

ASSIST PLUS: Magnetic Bead Purification automated with the ASSIST PLUS

Hi everyone, in this video, we want to show you how the ASSIST PLUS can be used to automate magnet EP Purification. Automating these protocols with this very affordable pipetting robot increases the reproducibility of your results and gives you more time to focus on your science.

The protocol starts with mixing the samples with the beads and allowing the DNA to bind to the beads. Then, washing steps are applied to remove unwanted unbound material, and finally, the bound DNA is eluted from the beads.

For this experiment, you will need the following materials: magnetic beads (here filled into a PCR strip), samples (here we process 24 samples), a magnet or magnets (standard plate format can be used), 70% ethanol, elution buffer, and of course, a pipette. This is the beauty of the ASSIST PLUS concept - you can click in any of our 25 electronic pipettes. We work here with the 8-channel VOYAGER pipette and 125 µl low-retention GRIPTIPS®.

For the first program, the deck is prepared with the beads, the sample wells, and the magnet. Additionally, we have a PCR strip for the waste. After re-suspending the beads, they are transferred to the samples and thoroughly mixed by pipetting up and down to ensure optimal binding conditions. To minimize the residual volume of beads in the tip, we highly recommend using low-retention GRIPTIPS®. 

In the 5-minute incubation time, the DNA binds to the beads. The plate is transferred onto the magnet and incubated for 2 minutes to allow for separation of the beads and the supernatant. The supernatant is carefully removed without disturbing the bead pellet.

The first program is now finished, and for the second program, we use an eight-row reservoir filled with 70% ethanol and elution buffer. The beads are washed by adding ethanol followed by a 30-second incubation time. While pipetting ethanol, droplets can form at the bottom of the tip, so to avoid dripping, we recommend using low-retention GRIPTIPS®. A second wash step is supplied, and the beads are washed again by adding ethanol and waiting for a 30-second incubation. After the final washing step, it is important to remove all ethanol from the sample to avoid any inhibitory effects in the final purified sample.

For sample elution, the plate has to be removed from the magnet, the elution buffer is added to the beads, and mixed until the beads are homogeneously resuspended. This is followed by another 2-minute incubation to allow the DNA to unbind from the beads. For the final transfer, the sample plate is placed again on the magnet to achieve magnetic separation, while a new plate is placed in position B. After a 1-minute magnetic separation, all the eluate is transferred to the fresh plate without any bead carryover.


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