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Plaque assay from enriched - refilter?

| posted 14 Sep, 2018 13:33
Quick question about setting up plaque assays from enriched for the first round of purification: If you have a positive spot test, and you are now going back to the enriched sample for dilutions, do you use the original filtered sample, or pull more from the enriched culture and filter a new sample? Both the original filtered sample and the enriched culture have been in the fridge for a week.
| posted 14 Sep, 2018 14:14
I use the filtered sample. Evaluate this choice if the number of plaques is <10 in the spot. In this case, I MAY carefully consider picking from the spot. I would also change the volume that I plate from the enrichment. The second consideration is if the spot is contaminated. You may want to refilter or you may have to go back to the original sample and carefully filter.
Good luck.
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