Hello, I'm curious to know - when we keep track of cell passages because they’re expressing a gene we care about, and if they’re passaged too many times, they lose that expression. Does the same thing happen with wild-type cells since they’re not overexpressing anything specific?"
Also, if we freeze the cells down, can we reset the passage count after thawing them? Or do we have to keep counting from where we left off before freezing?
No, we don't reset passage number after freezing/thawing. If you freeze down at passage 20, when you thaw, it's still at passage 20. When you passage again, it's now passage 21.
Also, yes, WT cells can change phenotype and gene expression with increasing passage number. While they may not lose transgene expression (since they don’t carry one), their endogenous gene expression and behavior can still drift, affecting reproducibility and experimental outcomes. Hence, it's critical to keep track of passage number even for WT cells.
Nope, once freezing down the cells, the passage cannot be reset upon thawing. and even for WT cells, phenotypic and gene expression (those endogenously expressed by the cells) may alter.
Erica Weber Yes, wild-type cells can also change over many passages though they’re not overexpressing a transgene, they may still undergo genetic drift, epigenetic changes, or phenotypic alterations like changes in growth rate, morphology, or responsiveness, especially in long-term culture. So tracking passage number is still important even for wild-type cells.
As for freezing: no, you don't reset the passage number after thawing. Cells retain their passage history, so you should continue counting from the passage they were at before freezing. This helps ensure consistency and reproducibility in experiments.
- Badges
- Science topic
- Similar topics
- Engineering
- Materials Engineering
- Powders