A common type of character is the prodigy scientist. This is someone who is extremely talented and often much younger than the rest of the team. They bring fresh ideas to the lab but may also face jealousy from others. Another character could be the ethical watchdog, a person who constantly questions the morality of the experiments being carried out in the laboratory. And don't forget about the visiting scholars or interns who add a different perspective to the lab's dynamics.
Well, in these visual novels, you'll often find the overworked and underpaid post - doc. They are the ones doing a lot of the grunt work but also hoping to make a name for themselves. There are also technicians who are responsible for maintaining all the complex equipment in the lab. And sometimes, there are corporate representatives who are interested in the commercial applications of the research, which can create a lot of tension as their goals may not align with the pure scientific pursuits of the lab members.