Can I apply for Postdoctoral Research Assistant as a fresh MSc graduate? I know it sounds stupid but I have applied for a Postdoctoral Research Assistant at a university in London and I have received an invitation for a Skype interview. However, I am a fresh MSc graduate having finished my masters two months ago. One of the job requirements says "PhD and/or equivalent professional experience" as essential skill, yet they invited me for a Skype interview. 

Now I am wondering if this was a mistake or am I just shortlisted??

Any help would be appreciated. Thanks in advance
Unfortunately I expect this is a mistake on the university's part. Many people apply for postdocs in the final year of their PhD, so perhaps they misinterpreted your CV and thought you were in that category.

There is likely to be a requirement in the formal job description that candidates must have, or be near to completing a PhD, so even if you were to attend and do well at the interview, I highly doubt they would be able to make you a job offer anyway.

My advice is to send them an email thanking them for the invitation to interview but clearly state that you do not have a PhD nor are you a current PhD student. It is likely they will rescind the interview offer.