By now you are probably aware of the importance of pre-treating stools samples to ensure maximum extraction efficiency. But did you know that inadequate vortexing of the pretreatment tubes can cause your parasitic samples to give false negative results?
Cryptosporidium and Giardia are parasites that contain a protective outer shell. This outer shell allows the organism to become resistant to environmental factors. Rigorous vortexing is critical in breaking open this outer shell to ensure efficient extraction.
We recommend vortexing the pretreatment tubes vigorously at a maximum speed for five minutes.
Mo Bio Laboratories, Inc. makes vortex adaptors (Cat. # 13000-V1-24) for your Vortex-Genie. What we love about this particular adaptor is that not only does it allow you to vortex up to 24 pretreatment tubes simultaneously, but it also orients the tubes in an angle that allows the beads to effectively break up any solid matter in the tube. This includes any parasites that may be in your sample.
Once the pretreated samples get aliquoted for extraction, the pretreatment tubes can be frozen at -80⁰C. To reuse the previously pre-treated tubes, simply thaw the tubes at room temperature. Once thawed, give each tube a quick 10 second vortex. Then centrifuge the tubes at 14,000 rpm for 2 minutes (to re-pellet the beads and any cellular debris). The samples are now ready to be extracted.
And that’s the scoop!