You can use a loading control to a housekeeping gene (B-actin, gapdh, etc) and calculate fold control to that,

Hello Visser,

Fold change calculation with respect to its housekeeping gene is the best way; another way is to keep one negative control. You can compare the potential to expresses the particular protein using two different simulations and can calculate the fold change. You can also use the time-dependent exposure of your stimuli and measure the changes in the folds of protein expression with respect to its untreated control sample, in that case, a lesser time of exposure may or may not show much differences when compared to control. However, the presence of the housekeeping protein expression will justify the loading controls of the respective sample.

Good luck.

Hi there,

If you can't get any protein level for your control there is no chance to calculate protein level amplification during stress as it would be a all or nothing situation. What you could do is to monitor the protein level change according to the dose of stress applied to the cells.

Hi Hartwig Visser ,

I think your result does not need to be expressed in terms of "fold-change". The result is very dramatic: no expression (0) versus expression. Do you have a standard for this protein? If you have, do a standard curve and transform your data for picogram/fentogram protein. Anyway your control will be 0, but you may feel better with this way to express results. :)

Housekeeping genes will not work for your specific problem. Why? Because if you do the ratios:

1) control protein signal (0)/housekeeping signal (any number) = 0

2) treated protein signal (any number)/housekeeping signal (any number) = any Real number, lets say 5

fold change = 5/0 - blue windows screen (annoying sound)

The result will be 0. Your problem is the 0. Dividing anything to 0 is impossible. Housekeeping (reference protein) is just for loading control correction.

Best,

Jacó