mikes is short of micrograms, used when talking about how much acid you taken or how good the acid is.
1)Duude i was soo messed up last night i most of takin 200 mikes of acid.
guy 1: hey man you want some acid?
guy 2: ya dude,is the shit any good?
guy 1: ya man its owsley shit, its 300 mics a hit