Hello Lee Jinkyu.

I don´t quite understand your question. Are your pictures affected by the flash? Do you see a big white circle, or are they somehow not evenly illuminated? If this is so, of course this affects the areas calculated. Most of these programs are based on threshold and pixel-counting. If you have a big white area on your pictures, then this might have an effect on the calculated area.

If you are wondering whether the flash per se has an effect on your cultures: I don´t think so. Although it has been shown that irradiation with 635 nm (a part of visible light) reduces intracellular ROS production in HUVECs, which results in increased angiogenesis (see publication below):

http://onlinelibrary.wiley.com/doi/10.1002/lsm.21038/abstract

Greetings

Dear Marcia Gasis,

Thank you for your answer!

I have no problem with my picture from flash.

So you mean that you think flash and other types of light are

not related to migration of HUVECs right?

Thank you again

Hello.

I think leaving the cells for prolonged time outside the incubator has a bigger effect than light.

Regarding light it depends on the duration you irradiate your cells and wavelength of the light. If you use UV, this could kill your cells since it damages the DNA...

But if you leave your cells for not too long under the microscope for picture-taking (bright field) then I don´t think this has a measurable effect on them.

Maybe someone else has an other opinion, he or she would like to share?

Greetings