Do I need to reinstall Mountain Lion if I upgrade my SSD?

Hello,

I have a Macbook Air 13" Mid 2011 with 128GB of storage. I am thinking about upgrading this limited storage capacity SSD on my Macbook Air to a much higher capacity SSD of around 400GB using an SSD available from OWC Computing. After reading guides for installing a new HDD on other laptops, I understand that it is necessary to reinstall the OS onto the new HDD. However the guide for installing a new SSD for Macbook Air does not mention reinstalling the OS.

My question is whether or not I have to reinstall the OS(Mountain Lion) onto the new SSD after I upgrade it.

Thanks for the help!

Cheers