Why do I have to use different magnetic devices for SPRI bead purification of cDNA?
Why do I have to use different magnetic devices for SPRI bead purification of cDNA?
The following magnetic devices, recommended in the user manuals for some SMARTer cDNA synthesis kits, have been validated for SPRI bead-based purification of cDNA in different types of tubes. You may also make your own magnetic separator using rare earth magnets.
For nuclease-free thin-wall PCR tubes (0.2 ml; USA Scientific, Cat. # 1402-4700):
SMARTer-Seq Magnetic Separator - PCR Strip, Cat. #635011
For 96-well V-bottom plates (500 µl; VWR, Cat. # 47743-996):
Magnetic Stand-96 (Thermo Fisher Scientific, Part # AM10027)
Using two devices ensures optimal separation of SPRI beads from the supernatant and avoids magnetic bead contamination of the cDNA prep, which may result in a distorted Bioanalyzer electropherogram. A very important reason to use two separate magnetic stands is to avoid cross-contamination in kits that require two bead-purification steps. One separation device should be located in the PCR Clean Work Station, while a second magnetic separation device should be located in the General Lab.