No, because the exposure of normal camera changes with what you are focussing on. As the gel changes, the exposure will change automatically, moreover even if you take same gel twice, the exposure will change within instances. Gel doc cameras are special cameras that have fixed exposure which can be set through softwares.

Even in Manual Ev mode in digital cameras the exposure control is relative to the main exposure picked up in automatic mode and isnt reproducible and reliable for quantitative purpose. Alternative solutions are softwares that can control exposure of your camera that supports USB operations.

One example is (Not tested)

http://www.nimisis.com/projects/exposure.php

The camera that is used is a special camera like one in this page:

http://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=4024

That gives full control over USB. and then either an open source software or custom made software can be used as a controller.

Another faulty approach is taking images and adjusting white after image production. though it happens even if you take images with gel doc, but one has to take care that the exposure that is set doesnt trip out the extreme black spots of gel, so that linearity between concentration and intensity is not lost at higher intensity. Usual gel doc softwares has option to indicate if the image exposure causes some tripping out.

I knew that the answer is NO because the image quality varies in both cases but for exact reason, I followed excellent explanation given by Mr. Saurabh Gayali and got a clear idea about the reason why we can not use the image from normal camera for quantitative analysis.

Thank you Saurabh & Ekta,

I think I asked the question in a bit confusing way. I did not meant here taking image using a normal camera. I wanted to ask that, what are the differences between an image taken with room temperature CCD camera and an image taken from super cooled CCD camera. I know that an image taken with a super cooled CCD (-30C) can be used for quantification but if i take an image with room temperature CCD camera how good that would be for quantification?

I am really sorry for wrong interpretation of the question.

"Cooling reduces the array's dark current, improving the sensitivity of the CCD to low light intensities, even for ultraviolet and visible wavelengths. Professional observatories often cool their detectors with liquid nitrogen to reduce the dark current, and therefore the thermal noise, to negligible levels."

Source- http://en.wikipedia.org/wiki/Charge-coupled_device

The image might be used, but sensitivity will be low. So if you are doing it for proteomic purposes, using supercooled CCD will cause more number of spots for identification in 2DE. while if you are quantitaing for westerno r some other single protein experiments, the normal temperature camera will also yield good results, untill and unless your protein is very very low concentration in the cell.