Labcorp is based out of Burlington, NC. (KBUY) and goes by the "SkyLab" call sign.

Quest goes by the call sign LabQuest.

Labcorp flies medical samples like blood.
PC12 (pre NG models) single pilot IFR
Flights are late afternoon to mid morning (mostly Mon-Fri with limited weekend flights)
2-4 legs per night out and back. Home every night.

Hope it helps.