SDS-PAGE Gel Calculator

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FREE TOOL

Resolving Gel % — Quick Presets

8% 10% 12% 15% 18%

Resolving Gel Acrylamide %

Typical range: 8–18%

Resolving Gel Volume (mL)

Total volume for resolving gel.

Stacking Gel Volume (mL)

Typically 2–4 mL for mini gels.

Number of Gels

Acrylamide Stock Concentration (%)

APS Stock Concentration (%)

🧫 SDS-PAGE Gel Recipe

⚗️ Resolving Gel Recipe

🔬 Stacking Gel Recipe (5% acrylamide)

Protein Separation Range Guide

Large proteins: 40–200 kDa8%

Medium proteins: 20–120 kDa10%

Standard proteins: 10–70 kDa12%

Small proteins: 5–40 kDa15%

Very small proteins: 3–20 kDa18%

How to Use the SDS-PAGE Gel Calculator

Select a quick preset acrylamide percentage (8%, 10%, 12%, 15%, 18%) or enter a custom value.
Enter the total volume needed for the resolving gel and stacking gel in mL.
Enter the number of gels to prepare — all volumes will be scaled accordingly.
Select your acrylamide stock concentration (30% or 40%) and APS stock (10% or 5%).
Click Calculate Gel Recipe to get exact volumes for every component.

About SDS-PAGE Gel Preparation

SDS-PAGE (Sodium Dodecyl Sulphate – Polyacrylamide Gel Electrophoresis) separates proteins by molecular weight. The gel consists of two layers: the resolving gel (bottom) and the stacking gel (top).

The resolving gel is prepared with Tris-HCl pH 8.8, acrylamide/bis, SDS, APS, and TEMED. The higher the acrylamide percentage, the smaller the pore size and the better the resolution of small proteins.

The stacking gel is always prepared at 5% acrylamide with Tris-HCl pH 6.8. Its lower pH and larger pore size concentrates all proteins into a sharp band before they enter the resolving gel.

APS (ammonium persulfate) initiates polymerisation and TEMED (tetramethylethylenediamine) acts as the catalyst. Always add these last and pour the gel immediately.

Choosing the Right Acrylamide Percentage

8%: Best for large proteins (40–200 kDa) — e.g. myosin, large transcription factors.
10%: Good for medium-range proteins (20–120 kDa) — most commonly used percentage.
12%: Good resolution for 10–70 kDa range — ideal for most recombinant proteins.
15%: Best for small proteins (5–40 kDa) — e.g. cytokines, small enzymes.
18%: For very small proteins and peptides (3–20 kDa) — requires careful handling.
Gradient gels (e.g. 4–20%): Wide separation range — not supported in this calculator but available as pre-cast gels.

SDS-PAGE Gel Calculator