User's Manual

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Chapter 5: Multiple Displacement
Amplification in droplets (dMDA)
Break sorted droplets (if applicable)
After sorting, keep the sorted dPCR droplets at 4°C and proceed immediately to dMDA amplification.
Do not store sorted dPCR droplets longer than 8 hours as this may lead to DNA degradation. If amplifying
already purified DNA, continue directly to “Set up dMDA reaction”, described on the next page.
After the enrichment step and sorting of selected DNA molecules from Xdrop™ dPCR droplets, release the
DNA from the sorted dPCR droplets by breaking the droplets with Break solution ● and Break colour ● as
described below.
1. Add 20 μl Break solution ● to each tube of sorted dPCR droplets.
2. Add 1 μl of Break colour ●. This will colour the water phase. If colouring is too weak, add 1 extra μl.
Note: The water phase may be a colour ranging from yellow to purple as the Break colour functions
as a pH indicator.
3. Flick tube gently, do not vortex.
4. Spin tube briefly (15-30 sec).
5. Remove the clear Break solution phase from the bottom of the tube and discard. Note: Be careful to
remove all the Break solution as it may inhibit downstream enzymatic reactions.
6. Repeat steps 3-5 to remove all leftover Break solution.
7. Keep the coloured water phase, which will contain DNA from the positive dPCR droplets (Fig. 5.1).
Fig. 5.1. Break sorted dPCR droplets with Break solution ● and Break colour ●. Discard the clear Break
solution phase at the bottom of the tube. Keep the top coloured water phase, this phase will contain your
DNA molecules.
Coloured water phase (keep)
Break solution phase (discard)