No it is a preposition.
No. It is a prepositional phrase. "In" is the preposition and "the lab" is, well, what it is in. At least, that is what i remember, i took that type of class last year.
What kind of phrase is "If you save your money
adjective phrase
More details are required to answer this question. What kind of lab?
adjective phrase
Verb phrase
adverb phrase
prepositional phrase.
lab
I have a black lab. You should give them tennis balls and ropes.
Please be specific, what kind of lab probe you are referring here?