| Close |
Message | User | Date(yyyy-mm-dd) |
|
|---|
|
excessive cell growth | mjsousa | 2008-06-17 | Click here to register. |
|---|
I am in the process of transfering a bioassay to my lab from another lab that has been performing the assay successfully for some time. This lab is in CA and I am in MA. We are both following the same protocol and using the same reagents, but I have 2X more cells at time of seeding my plates than does my counterpart. Any idea what could be leading to this exagerated growth. We have ruled out the FBS. I have recently resorted to seeding my flask with 50% fewer cells to start than the lab in CA. That seems to deliver more favorable results. Also, it appears that the excessive grwoth has been the reason for my irradic assay results. Is this possible and if so what about the excessive grwoth would cause it. Does the overabundance of cells create conforamatinal changes in the cells / alter binding sites somehow???
Any informatin any one can provide will be tremendously appreicated.
thanks
Julie | | |
| lubrol | 2008-06-26 | Click here to register. |
|---|
 | Some thing to consider:
You say that you are using the same reagents: does that mean the same lots or just the same supplier catalog number? I know if sounds silly, but lots can vary a lot for reagents other than serum.
When you say that you have ruled out the FBS; does that mean that you have swapped samples?
Are you using the same brand and size of plates?
Are the incubators set to the same temperature and with the same level of CO2?
Are you splitting the cells using the same exact protocol (reagents, times, concentrations, times, centrifuge RCF)?
Are you using the same procedure and equipment to count your cells after harvesting to determine the seeding density?
Do the two labs harvest the cells at the same level of confluency or is it based on the same period of time in culture?
Are the cultures kept in a dedicated incubator or is it shared with other users, cultures, labs? How frequently is the incubator opened to retrieve plates/flasks and does this differ between the two facilities?
The erratic assay results could certainly be a result of the higher cell numbers as contact inhibition of cell growth is dependent on density. If the assay is sensitive to the cell cycle or level/type of metabolism in the cells, the quantities of cells could certainly influence the performance. This can be even more of an issue if the cells are normally contact inhibited as the metabolism changes significantly upon contact with other cells. If the cells are not contact inhibited (most, if not all, tumor derived lines are not) the metabolism will still change but in different ways as the cells begin piling up into a multi-layer condition.
Sorry that I have more questions than answers right now. |
| | |
| n@@n! | 2008-07-29 | Click here to register. |
|---|
| When we thaw a cell line from a stock, it takes intially longer periods of time to pickup the growth. Initially the number of cells will be less in a defined time. But at a later stages (as the number of passages increase) the cells tends to grow exponentially within a short period of time. Cell number seems to be more in a defimed time, in comparision to intial stages of growth.
However, it differs from one cell line to the other. I am not sure about the type of cell line that you are using.
This may be a possibility. |
|
|
| Thanks for visiting.- To ask or answer a question, you need to register here.
- You can browse by clicking on a message subject to see the complete message.
- If you have previously registered, you can log in below.
|
|
Back to Top
Oldest