You can reach the end of the lab area (it is painfully long), in fact next update will take you to the sewers area
The laboratory is currently not very balanced.
The best way to do it would be to get a ton of stamina, even more energy drinks and spam skills which give you better accuracy and prevent enemy specials.
Having the gun guy (forgot his name) helps because sometimes he'll come in and clutch the fight while you're stunlocked.
Effective use of the talk commands will offset the damage discrepancy, though getting ganked by the assimilator with one of the others will sometimes still screw you if she locks your enrage skill.
That being said, another boost is cooking. Eating (I believe meat or dough?) boosts your base damage before the damage range allotted by your stamina level, so you'll be hitting for 15 on the regular with the pizza/ramen from hell with everything on it (including water and noodles)