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Cell Dilution Calculator

Dilute a cell suspension fast and correctly — whether you’re aiming for a target cells/mL, prepping a plate seeding mix (cells/well × wells), or making a serial dilution series. Uses C₁V₁ = C₂V₂ and shows steps, quick picks, plus a mini mix visual.

Background

Most cell dilution problems are just conservation of “cells” in a mixture: the number of cells pulled from stock equals the number of cells in the final mix. That’s why C₁V₁ = C₂V₂ works so well for lab prep.

Enter values

Tip: “Target concentration” is the classic C₁V₁ = C₂V₂ setup.

Assumed units: cells/mL.

Units: cells/mL.

We’ll output stock volume and diluent volume.

We compute total mix volume and the stock volume needed to supply the total cells.

Adds extra volume to cover pipetting loss.

Units: cells/mL (this can be different from C₁ if you want).

Example: “10×” means each step is 1/10. “1:5” means each step is 1/5.

If provided, we’ll show “transfer” and “diluent” volumes for each step.

Options

Chips prefill values and calculate immediately.

Result

No results yet. Enter values and click Calculate.

How to use this calculator

  • Choose a mode: Target concentration, Plate seeding, or Serial dilution.
  • Enter values (stock concentration is in cells/mL).
  • Click Calculate to get volumes, a mix visual, pipette callouts, and step-by-step.

How this calculator works

  • Core idea: cells are conserved in the mix.
  • Dilution equation: C₁V₁ = C₂V₂
  • Seeding: total cells = cells/well × wells (then solve for Vstock = Ntotal / C₁).
  • Serial: each step divides concentration by the factor.

Formula & Equation Used

Dilution: C₁V₁ = C₂V₂

Stock volume: V₁ = (C₂·V₂)/C₁

Diluent volume: Vdiluent = Vfinal − Vstock

Seeding total cells: Ntotal = (cells/well)·(wells)

Example Problems & Step-by-Step Solutions

Example 1 — Target concentration (classic C₁V₁ = C₂V₂)

  1. Goal: Make 10 mL at 200,000 cells/mL from a stock of 1,200,000 cells/mL.
  2. Use C₁V₁ = C₂V₂ → V₁ = (C₂·V₂)/C₁.
  3. Compute stock volume: Vstock = (200,000·10)/1,200,000 = 1.6667 mL.
  4. Compute diluent volume: Vdiluent = 10 − 1.6667 = 8.3333 mL.
  5. Pipette 1.667 mL stock + add 8.333 mL media/diluent → total 10 mL.

Example 2 — Plate seeding (cells/well × wells + overage)

  1. Goal: Seed a 96-well plate at 10,000 cells/well, 100 µL/well, with 10% overage.
  2. Total volume (no overage): 96·100 µL = 9,600 µL = 9.6 mL.
  3. Apply 10% overage: Vtotal = 9.6·1.10 = 10.56 mL.
  4. Total cells needed: Ntotal = 10,000·96·1.10 = 1,056,000 cells.
  5. If stock is 1,000,000 cells/mL: Vstock = 1,056,000 / 1,000,000 = 1.056 mL, so Vmedia = 10.56 − 1.056 = 9.504 mL.

Example 3 — Serial dilution (10× for 6 steps)

  1. Start: 1,000,000 cells/mL, do a 10× dilution for 6 steps.
  2. Each step: Cnext = Cprev / 10.
  3. Concentrations: Step 0 = 1,000,000 → Step 1 = 100,000 → Step 2 = 10,000 → Step 3 = 1,000 → Step 4 = 100 → Step 5 = 10 → Step 6 = 1 (cells/mL).
  4. If tube volume is 1 mL each step: transfer 1/10 of the tube: Vtransfer = 1 mL / 10 = 0.1 mL = 100 µL, add 900 µL diluent.

Example 4 — Tiny stock volume → intermediate dilution (real lab fix)

  1. Goal: Make 1.0 mL at 10,000 cells/mL from a stock of 10,000,000 cells/mL.
  2. Direct calculation: Vstock = (10,000·1.0)/10,000,000 = 0.001 mL = 1 µL (too tiny for many students).
  3. Make an intermediate dilution first (example: 1:10): mix 10 µL stock + 90 µL media → new stock is 1,000,000 cells/mL.
  4. Now recompute with intermediate stock: Vstock = (10,000·1.0)/1,000,000 = 0.01 mL = 10 µL.
  5. Pipette 10 µL (much more accurate) + add 990 µL media → 1.0 mL final.

Example 5 — Plate seeding (24-well, bigger volume, no overage)

  1. Goal: Seed a 24-well plate at 50,000 cells/well with 500 µL/well, no overage.
  2. Total volume: 24·500 µL = 12,000 µL = 12 mL.
  3. Total cells needed: Ntotal = 50,000·24 = 1,200,000 cells.
  4. If stock is 1,500,000 cells/mL: Vstock = 1,200,000 / 1,500,000 = 0.8 mL.
  5. Media volume: Vmedia = 12 − 0.8 = 11.2 mL.

Tip: Use the Quick picks above to load the main scenarios instantly.

Common mistakes (and quick fixes)

  • Units mismatch: mixing µL and mL — always sanity-check the output units.
  • Trying to “dilute up”: if C₂ > C₁, you can’t reach it by dilution.
  • Tiny stock volume: if stock is < 2 µL, make an intermediate dilution first.

Frequently Asked Questions

Q: What does “cells/mL” mean?

It’s the concentration of cells in your suspension — how many cells are in 1 mL.

Q: Why is the answer sometimes in µL?

Stock volumes are often small, so we auto-display tiny volumes in µL for readability.

Q: What’s overage?

Extra volume added to cover pipetting loss (common: 5–15%).

Q: What if my stock volume is < 2 µL?

That’s below what many students can pipette accurately. Make an intermediate dilution (e.g., dilute the stock first), then pipette a larger, more accurate volume.