No specific extraction method is required for MLPA, as long as the DNA is sufficiently pure.
Most standard extraction methods yield DNA of sufficient quality for use in MLPA experiments. Extraction methods should not leave a high concentration of impurities in the DNA sample (see this article for more information). In addition, DNA should be eluted/resuspended in a solution with sufficient buffering capacity, such as elution buffer or TE, and not in water (see this article for more information).
MRC Holland has tested and can recommend the following extraction methods:
- QIAGEN Autopure LS (automated) and QIAamp DNA mini/midi/maxi kit (manual).
- Promega Wizard Genomic DNA Purification Kit (manual).
- Salting out (manual).
However, our customers use a wide range of different extraction methods successfully.
Many of our customers successfully use automated extraction methods in combination with MLPA. Some automated systems are not suitable for extraction of samples for MLPA as too much residual salt is left in the samples (e.g. the QIAGEN M6, M48 and M96 systems).
If you are using the QIAGEN EZ1 for DNA extraction, use the QIAGEN Supplementary Protocol: Purification of genomic DNA from whole blood, optimized for use in MRC-Holland MLPA® assays, using EZ1® DNA Blood Kits.
Magnetic bead-based systems
DNA extracted with magnetic bead-based systems works well with MLPA. Prior to April 2019, iron ion contamination from the magnetic beads could result in sloping, but our reagents have since been modified to address this issue.
Heparinised blood can be used, but only when the sample has undergone a purification method to remove the heparin contamination (e.g. Nucleospin gDNA Clean-up XS).
Dried blood spot cards
MLPA on DNA derived from dried blood spot (DBS) cards, and the use of dried blood spot cards in combination with MLPA, has not been approved for in vitro diagnostic use for most probemixes, unless explicitly stated otherwise in the intended use.