Laboratory solution tools

Enzyme formulation & laboratory calculator.

Build enzyme formulations and fermentation media, calculate ingredient quantities for any batch size, and use the supporting dilution, molarity and molecular-weight tools when needed.

Unit note: 1% w/v is treated as 10 mg/mL. g/L and mg/mL are numerically equivalent. The target concentration must not exceed the stock concentration.
Stock solution required
10 mL
Diluent required90 mL
Final volume100 mL
Dilution factor10×
V₁ = (C₂ × V₂) ÷ C₁
Diluent = V₂ − V₁
Mass required = molarity × volume × molecular weight.
Mass required
5.844 g
Moles required0.1 mol
Concentration0.1 M
mass (g) = concentration (mol/L) × volume (L) × MW (g/mol)

Build your formulation

Enzyme formulations: choose “Enzyme activity (U/mL)” and enter the stock activity to calculate the volume of enzyme concentrate required. For complex media ingredients such as tryptone, yeast extract and corn steep liquor, use mass or volume-based specifications rather than molecular weight.

Ingredient list

No ingredients added yet.
Choose a final batch volume, then add enzymes, media components, buffers and formulation ingredients.

Quick formulation presets

Phosphate buffer

Add KH₂PO₄ / K₂HPO₄ components and calculate the required mass for your batch volume.

Fermentation media

Build recipes using glucose, glycerol, tryptone, yeast extract, salts and other media components.

Enzyme formulation

Combine enzyme concentrate with glycerol, buffer, salts, preservatives or other formulation ingredients.

Stabilised liquid product

Build a liquid formulation using glycerol or propylene glycol alongside the active enzyme and buffer system.

Beer–Lambert law: A = εcl. Use an extinction coefficient appropriate to the analyte and wavelength being measured. Absorbance is dimensionless.
Calculated concentration
0.000016 mol/L
Absorbance0.8
Extinction coefficient50,000 L·mol⁻¹·cm⁻¹
Path length1 cm
A = ε × c × l

Common media references

LB broth

Typical formulation: tryptone 10 g/L, yeast extract 5 g/L and NaCl 5–10 g/L depending on the LB variant.

2×YT

Typical formulation: tryptone 16 g/L, yeast extract 10 g/L and NaCl 5 g/L.

Terrific Broth

Typical formulation: tryptone 12 g/L, yeast extract 24 g/L, glycerol plus phosphate buffering.

M9 minimal medium

Defined medium commonly based on phosphate salts, NaCl, NH₄Cl, MgSO₄, CaCl₂ and a chosen carbon source such as glucose.

SOC medium

Rich recovery medium commonly containing tryptone, yeast extract, NaCl, KCl, Mg²⁺ salts and glucose.

Phosphate buffer

KH₂PO₄ / K₂HPO₄ or sodium phosphate systems are commonly used where controlled phosphate buffering is appropriate.

Acetate buffer

Acetic acid / sodium acetate systems are useful for acidic pH ranges; calculate defined components using the exact chemical form used.

Tryptone and yeast extract are complex mixtures and do not have a single meaningful molecular weight. Hydrated salts must be matched to the exact hydrate form used when calculating molarity.