No worries.... I expect them to ask you about your work status during the interview. If they can't hire you because of your F1 status, they will advise you accordingly. From what I have seen before, they have hired many full time post-docs on their OPT status. I think the citizenship requirement is for regular job, not for fixed term contract jobs. Good luck for your interview.

* Disclaimer: I am not lawyer and take this advice on your own risk.

Purana,

Why are you worrying about your status? You should be worried about your interview rather. Be prepared and go to the interview, no need to ask stupid question like, "Do you guys hire F1?"

Yes, most government organization want US citizenship but not all. The one's that require US citizenship will have it noted in the job posting.

I see that you have nothing to lose even if they don't hire non US citizen. It will be a good experience for you to go through the process. You have nothing to lose beside couple of hours.

You only need to show eligibility to work after you are offered the job which you can easily by getting your CPT.

Good luck.

you can certainly do an internship. One of my friends worked for my state govt last summer. They will probably not hire you for fulltime though

Thank you so much guys....I've little hope now.
Goreto,
The reason i am not worried about the interview is because i am 90% confident that i'll get this internship unless my F1 status does any turn around. I had phone conversation with the guy who was interested on bringing me as an Intern at CDC and he looks very interested and pretty much guaranteed..