What does "If the lab room disposable cover fits" means ?
I watching "The Big Bang Theory"- and I cam up with this. What does that mean? Here are the dialogues :

Amy: I’m sorry, are you questioning my integrity as a scientist?
Sheldon: If the lab room disposable cover fits.
Penny: Was that a science diss?
Leonard: Yeah.
Penny: Was it a good one?
Leonard: Eh.
Penny: Ah.* what does "science diss" means?

Question

What does "If the lab room disposable cover fits" means ?
I watching "The Big Bang Theory"- and I cam up with this. What does that mean? Here are the dialogues :

Amy: I’m sorry, are you questioning my integrity as a scientist?
Sheldon: If the lab room disposable cover fits.
Penny: Was that a science diss?
Leonard: Yeah.
Penny: Was it a good one?
Leonard: Eh.
Penny: Ah.* what does "science diss" means?

Answer

@David Butler, thanks I got the meaning.

Answer

Hi Bhuiyan, it is based on an English saying, "If the shoe fits, wear it."  The Big Bang writers have changed it to "If the lab room disposable cover fits."  It's a bit hard to explain - if I said "People who smoke cigarettes are rude", and you said to me "But I smoke," then I could say to you "If the shoe fits".  In other words, if what I have said applies to what you do, then admit it.  Sorry, this is difficult to explain! :-)

Answer

It's a variation of the phrase, "if the shoe fits..."

I'm sure you can look up the rest. ;)