Bruce didn't like any weapons. Mostly because he's had the majority trained on him. Being thought of as a weapon by Shield doesn't always sit well with him either, but he copes enough to get by.
The cells look normal enough. Bruce does a few tests to see how they react to things like adrenaline, pathogens, etc. Without looking up from the microscope, he says, "You don't get sick, do you? Your white blood cells are very aggressive."