RE9 Blood Lab Puzzle: Microscope Analysis Sequence Explained

The Blood Lab puzzle is one of the mandatory puzzles in Resident Evil Requiem. You’ll need to use a laser microscope to analyze blood specimens by solving a block-flipping logic puzzle. It sounds complicated, but once you know the sequence, it takes about ten seconds.

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Blood Lab Location

Where it is: East Wing of Rhodes Hill Chronic Care Center

How to get there:

1. From the main hall, head to the East Wing
2. Pass through the waiting room
3. Enter the Blood Lab

Heads up: The East Wing has enemies. Come prepared.

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Blood Specimen Types

Reversible Blood Specimen

• Availability: All difficulty levels
• Location: On the lab table or nearby in the Blood Lab
• Required for: Main story progression

Polymerized Blood Specimen

• Availability: Insanity difficulty only
• Location: Closet behind the Level 1 locked door near the waiting room
• How to access:
  1. Find the Level 1 door near the waiting room
  2. Unlock it with the appropriate key or code
  3. The specimen is in the closet inside

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How the Microscope Puzzle Works

The microscope shows a grid of colored blocks. The mechanic is similar to the classic “Lights Out” puzzle:

• Clicking a block changes that block and all adjacent blocks
• The goal is to get all blocks to the same color
• Order matters — you need the right sequence

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Solutions

Reversible Blood Specimen Solution

Click order:

1. Bottom-left block
2. Center block
3. Top-right block
4. Second block from the top

Step-by-step:

1. Place the Reversible specimen in the microscope
2. Activate the microscope to enter analysis mode
3. Click the bottom-left block
4. Click the center block
5. Click the top-right block
6. Click the second block from the top
7. All blocks should now be the same color — puzzle solved

Polymerized Blood Specimen (Insanity Difficulty)

The Polymerized specimen uses the same underlying mechanic but with a more complex starting pattern. General approach:

1. Observe the initial block configuration
2. Start from the corners — they affect fewer adjacent blocks
3. Work row by row toward the center
4. Adjust as needed based on what changes

Why Insanity adds it: the Polymerized analysis is the difficulty’s way of padding the puzzle with a second logical layer rather than a second code. If you solved the Reversible one by memorizing our sequence, this one is your chance to actually apply the mechanic — and since retries are unlimited, brute force is a legitimate strategy. Try a corner-first pattern, note what changed, reset, and refine.

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Puzzle Mechanics Deep Dive

Why This Works

The Blood Lab puzzle is a variant of the “Lights Out” logic puzzle:

• Each click affects a cross-shaped area (the clicked block + its four neighbors)
• The key insight: the order of clicks matters
• The provided sequence is the optimal solution for the Reversible specimen’s starting configuration

General Strategy (If You Want to Solve It Yourself)

1. Note the starting state — take a screenshot or sketch it
2. Start with corners — corner blocks have fewer neighbors, giving you more control
3. Work row by row — solve the top row, then use it as a reference for the next
4. Don’t panic — you can always reset and try again

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Common Failure Points

Even with the sequence in hand, players get stuck on three specific things:

1. Mixing up “second from top.” The fourth click is the block second from the top of the grid, not the second block you’d click going down. Count rows from the top edge before committing.
2. Clicking fast. The interface registers clicks in order, but double-clicks happen more often than you’d think on the center block. One deliberate click per block.
3. Assuming the puzzle failed. There’s no fail state. If the colors look wrong, exit and re-enter — a fresh grid resets to the known starting configuration.

The Level 1 Locked Door, Briefly

Insanity players need the Level 1 locked door near the waiting room open before the Polymerized specimen is reachable. The unlocking method is part of the East Wing progression — check drawers and desks in the rooms you’ve already passed, since RE9 consistently places keys one room behind the doors they open. If you’re sweeping everything, the all file locations guide doubles as a room-by-room checklist.

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Getting to the Blood Lab

Route from Main Hall

Main Hall
    ↓
East Wing corridor
    ↓
Waiting Room
    ↓
Blood Lab

Before You Go

• Bring ammo: Enemies patrol the East Wing
• Check your inventory: Make sure you have space for the specimen
• Save first: Use the nearest typewriter before tackling the puzzle area

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After Solving the Puzzle

What Happens Next

Completing the Blood Lab puzzle:

• Advances the main story
• Reveals critical information about “The Girl”
• Unlocks access to new areas
• Provides key items for later sections

Story Significance

The blood analysis results are central to Grace’s storyline — they explain the nature of the infection and hint at the truth behind the events at Rhodes Hill. Don’t skip the cutscene.

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Quick Reference

Specimen	Click Order
Reversible (all difficulties)	Bottom-left → Center → Top-right → 2nd from top
Polymerized (Insanity only)	Work from corners inward, row by row

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Wrapping Up

The Blood Lab microscope puzzle is one of those RE puzzles that looks intimidating until you know the answer — then it’s trivial. Four clicks in the right order and you’re done. If you’re on Insanity difficulty, the Polymerized specimen adds a bit more challenge, but the same logical approach applies. Now go solve it and find out what’s really going on with “The Girl.”

Quick reference:

• Reversible: bottom-left → center → top-right → second from top
• Polymerized (Insanity): corners first, row by row, unlimited retries

For every other puzzle in the campaign on one page, see the all puzzle solutions guide, and if you’re hunting trophies alongside the story, the platinum guide keeps the collectible checklist next to it.