quantify fluorescence in transfected cells using confocal and active contours

[violai...@hotmail.fr]

Hello
I would like to analyse fluorescent staning intensity - acquired in channel 0-  (after fixation and labeling) of transfected cells (visualized in channel 1) in comparison to control cells (not fluorescent in channel 1).
For this I acquired stack of images in confocal microscopy. To select a ROI, I used active contours around a transfected cell.
  -  Such ROI does it correspond to the whole transfected cell as I hope (corresponding to ecery surface of each z plan) ?
  -  In that case can I determine  numbers of pixels (in channel 0) per unit of volume in both cases, transfected and-non transfected and compare?
  -  Can I find the whole content of pixels in the cell in excel export as beeing "interior pix" or "sum of intensiy"? The indicated standard deviation is for which value?
Thank you very much for your advices
I could not join the stack, instead find a screenshot of a slice, and an excel file for the ROI
Violaine