Transfection Volume Calculator — Lipofectamine 3000 / PEI Scaled by Growth Area

When switching culture formats, transfection volumes scale with growth area, not well number.

Complex uptake by cells depends on complex density per unit area, so the only reliable basis for scaling is growth area per well (cm²):

Volume for format = 6-well per-well volume × (format area ÷ 9.6)
Master mix total  = per-well volume × number of wells × 1.10  (10% overage)

9.6 cm² is the nominal growth area of a single well in a 6-well plate.

Growth Area

Values are from Gibco’s Useful Numbers for Cell Culture. The culture vessel converter on this site uses the same table; the two pages will not give conflicting numbers. (Other manufacturers’ plates differ slightly — Corning lists 9.5 cm² for a 6-well and 3.8 cm² for a 12-well; the difference is a percentage point or two, but mixing two manufacturers’ values on the same site would create internal contradictions.)

Lipofectamine 3000 — 6-well plate reference volumes

Per the manufacturer’s protocol table, a single well of a 6-well plate uses:

Note that P3000 follows DNA, not area: it is calculated at 2 µL/µg DNA. Once DNA is scaled by area, P3000 scales with it, but the ratio is always 2.

Verification

Cross-check against the 24-well row of the manufacturer’s table:

Area factor = 1.9 ÷ 9.6 = 0.198
DNA           2.5 × 0.198 = 0.495 µg   (table: 500 ng)
Lipo3000      7.5 × 0.198 = 1.48 µL    (table: 1.5 µL)
P3000         5   × 0.198 = 0.99 µL    (table: 1 µL)

All three are within 1% of the manufacturer’s table values. The small discrepancy comes from the manufacturer rounding 0.198 to 1/5, not from any flaw in the scaling formula. This confirms that “scale volumes with area” is internally consistent with the manufacturer’s own multi-format values.

PEI

PEI volume (µL) = DNA (µg) × ratio

With a 1 mg/mL stock solution, µg and µL are numerically equal, which is convenient. The default ratio is 3 (µg PEI / µg DNA); the typical range is 2–4 and should be optimized per cell line. Consensus on PEI amounts is far less established than for Lipofectamine; treat these values as a starting point, not a final answer.

Using a different reagent

Select “Custom reagent” and enter the 6-well plate DNA and reagent reference amounts from your product insert; the calculator will scale to other formats by area. Presets for Lipofectamine 2000 and similar products are not included because published values differ considerably (protocols at 4, 10, and 15 µL exist for the same product); entering the value from your own insert is more reliable than a generic default.

Scope

• Reference values apply to transient transfection of adherent cell lines. Stable integration requires different amounts and ratios.
• Primary cells, suspension cells, T cells, and neurons generally require specialized reagents or electroporation; this scaling approach does not apply.
• For plasmids larger than 8 kb, GC-extreme sequences, or linearized DNA, optimal ratios must be determined empirically.
• This tool covers complex preparation only. Seeding density and medium-change timing also affect efficiency and are outside its scope.

Related tools

For cross-vessel scaling of cell counts and medium volumes, see Culture Vessel Converter; for converting plasmid concentration from OD₂₆₀, see Nucleic Acid Concentration Converter; for passage ratios and regrowth time, see Cell Split Ratio.

Growth area values from Gibco’s Useful Numbers for Cell Culture; Lipofectamine 3000 volumes from the publicly available Thermo Fisher reagent protocol.