Navigating the subterranean NEST facility in the Resident Evil 2 remake presents players with several intricate puzzles that are vital for story progression. Among these challenges, synthesizing the herbicide inside the Drug Testing Lab stands out as a crucial objective during your exploration of the East Area. Understanding how to locate the necessary access codes and execute the correct fluid transfer sequence ensures a smooth playthrough without wasting valuable resources.
Where to Find the Drug Testing Lab and Terminal
The Drug Testing Lab is situated in the East Area of the underground NEST research facility. Players access this room directly through the main corridor adjacent to the Greenhouse Control Room. Inside, you will find the Dispersal Unit workshop where the Plant 43 herbicide must be mixed and prepared.
Before you can interact with the herbicide synthesis machine, you must unlock the Dispersal Unit keypad located in the Greenhouse Control Room. Unlocking this console requires entering specific symbol combinations found hidden throughout nearby facility rooms. Keeping track of your story scenario is essential, as code solutions vary between First Run and Second Run playthroughs.
Locating the Keypad Codes in NEST
The first code required at the control console is printed directly on the hatch cover in the Greenhouse. Inputting this symbol sequence opens the ladder leading down into the facility basement. Navigating through the basement allows players to secure the DNA helix-shaped trophy containing the second code.
To reveal the second solution, examine the bottom of the DNA trophy within your inventory screen. In a First Run scenario, the trophy is located in the basement Lounge area. During a Second Run playthrough, the trophy can be retrieved inside the Low-Temperature Testing Lab near the cooling equipment. Entering this code into the control terminal activates the liquid mixing terminal inside the Drug Testing Lab.
First Run Herbicide Puzzle Solution
Once the Dispersal Unit is powered, insert the empty Dispersal Cartridge into the Drug Testing Lab machine. Your primary objective is to transfer liquid between three distinct tubes until the fluid reaches the red indicator mark. The control panel features three colored buttons—Red, Green, and Blue—that dictate liquid movement and column alignment.
For a standard First Run playthrough, hit the buttons in a specific repeating pattern to balance the tube volumes properly. Press the buttons in this exact order: Red, Green, Blue, Red, Green, Blue, Red, Green. Completing this sequence fills the cartridge to the exact red line, allowing you to retrieve the synthesized solution for cooling.
Second Run Herbicide Puzzle Solution
Players attempting Scenario B will encounter a rearranged starting volume in the liquid tubes. Because the starting positions differ from the primary campaign, the button combination required to solve the puzzle changes entirely. Following the updated sequence avoids unnecessary resets and saves valuable time during speedruns.
When operating the terminal on a Second Run, press the buttons in the following sequence: Blue, Red, Green, Blue, Red, Green, Blue, Red, Green. Once the solution reaches the marked threshold, take the filled cartridge down to the Low-Temperature Testing Lab to freeze it before dispersing it in the Greenhouse.
