In the literature there are all sorts of time points some do weeks and some do several months, would it depend on the cell injected? how long would it be reasonable to estimate an experiment to be negative (if you leave the mouse alive for too long it may have tumors unrelated with your experiment).
Usually you wait till they reach a certain size. And the amount of time depends on the cell line used when doing xenografts studies.
Although the time of tumor formation depends on many factors such as type and amount of cells to be injected as well as immunological status of the host, however, generally within a month most of tumor formation related phenotype appears. If it is not then you should take that experiment to be negative and try to optimize the other parameters such as cell number to be injected.
The time you wait depends on many factors as Anup has stated. It depends on how much test agent you have. It depends on if the tumor load in the controls becomes so high that you have to euthanize the animals. It depends on if you see an effect, and you want to get statistically significant data so you extend the time of the experiment. It depends if you just want to look at primary growth vs. metastasis or both. It depends on the cell line or model you use, etc etc.
There is a publication on this in Nature Protocols: http://www.nature.com/nprot/journal/v2/n2/full/nprot.2007.25.html
- Badges
- Science topic
- Similar topics
- Medicine
- Oncology
- Cancer Research