Inside the lab, your primary objective is to destroy the T-Virus samples. The lab is divided into several sections, each containing multiple sample containers. These containers are marked on your mini-map. Approach each container and interact with it to plant an explosive charge. Once planted, move away quickly as the explosion can damage you.
Expect heavy resistance from Umbrella Security Guards (USG) who are still loyal to the facility's original purpose. These guards are armed with firearms and will take cover. Use your own cover effectively and prioritize targets. Headshots are still the most efficient way to deal with them. After destroying a few samples, Lickers may appear. These creatures are fast and deadly; focus fire on their exposed brains when they lunge. A well-placed grenade can also stun them, allowing for easier takedowns. Continue destroying all marked samples until the objective is complete.