# How to perform a growth curve? - i need to compare 3 cell lines for growth (Mar/23/2009 )

Hi all,

I know i am asking a pretty basic question but i would like some advice or remarks on how to perform a growth curve for cells.

Basically i have 3 cell lines (derived from the same cell type) which we have developed which all seem to grow at different rates for which i would like to establish some growth curves for.

Does anybody have any suggestions on how to do this?

What starting number of cells should i use, what flask size should i use, how long should i run the experiment for?, should i measure cell number every day?

The thing is not all cells are the same size, two of the lines are fibroblast like, wheras one grows larger before they divide (can be 3 or 4 times as big as the other cell lines)

This would then have effects on growth as a confluent T75 of the smaller cells would have much more cells than a confluent flask of the larger cells.

As far as i am aware the cells dont need to much company to grow well, as i know some cells grow quicker when in contact with other cells, which means i could start at a low density in a T 75 which probably wouldnt be confluent for a week maybe.

Would this be an ok time frame? Say trypsinising everyday to take a sample for a count before reseedeing into a fresh T75?

Any advice or suggestions would be great.

Cotchy.

cotchy on Mar 23 2009, 08:30 PM said:

I know i am asking a pretty basic question but i would like some advice or remarks on how to perform a growth curve for cells.

Basically i have 3 cell lines (derived from the same cell type) which we have developed which all seem to grow at different rates for which i would like to establish some growth curves for.

Does anybody have any suggestions on how to do this?

What starting number of cells should i use, what flask size should i use, how long should i run the experiment for?, should i measure cell number every day?

The thing is not all cells are the same size, two of the lines are fibroblast like, wheras one grows larger before they divide (can be 3 or 4 times as big as the other cell lines)

This would then have effects on growth as a confluent T75 of the smaller cells would have much more cells than a confluent flask of the larger cells.

As far as i am aware the cells dont need to much company to grow well, as i know some cells grow quicker when in contact with other cells, which means i could start at a low density in a T 75 which probably wouldnt be confluent for a week maybe.

Would this be an ok time frame? Say trypsinising everyday to take a sample for a count before reseedeing into a fresh T75?

Any advice or suggestions would be great.

Cotchy.

Actually, you could find many references in Cancer Research.

Based on my own experimences, I used 6-well dish to prepare cells for growth curve. 50000 or 100000 cells per well (depending on the growth rate of your cell lines), 6 time points (5 days for counting plus the first day for seeding), triplicate wells for each time points. After preparing cells, you only need trypsinize cells and count the number at each time points everyday.

May it help you and good luck.

Thanks for the advice WOW however my cells grow pretty quickly and even 50,000 cells would be confluent in a 6 well plate after 5 days but again thanks for the advice i will take it on board but may use a T 75 also.

Cotchy.