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Restriction Cloning & Plasmids

Transformation Plate Normalization Workbench

Normalize one or more entered selective-plate colony counts for recovery volume, plated volume, pre-plating dilution and transformed DNA mass, then retain every plate-specific CFU/µg estimate.

Biology · experimental measurements

Expose the full plated-fraction denominator and technical-plate aggregation without treating colony yield as a universal cell property or correcting for viability, background and protocol differences.

Private calculations in your browser · explicit inputs and model boundaries
Example preview · One platePlate-specific normalized CFU/µg estimates
10^-2 plate1,500,000,000 CFU/µg

Each bar expands its own observed colonies by its entered dilution and plated fraction before dividing by the shared DNA mass.

  1. 1EnterProvide the known values
  2. 2CalculateResults update automatically
  3. 3VerifyReview the details and units
Try an example

Enter values in ng.

Enter values in µL.

Plates: label, colonies, pre-plating dilution fold, plated volume µL
1 row
Row 1

Empty rows are ignored until edited. Keep commas and tabs out of individual entries; use the paste view for comma- or tab-separated records.

Calculation result

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Understand the relationship

The reasoning behind the result

Only a fraction of the suspension is observed

fraction plated = plated volume/(recovery volume×dilution fold)

The observed colonies are expanded by the reciprocal sampled fraction.

The equation assumes the sampled suspension was homogeneous and the dilution was applied as entered.

DNA mass supplies the reported denominator

TE = estimated transformants/µg DNA

The mass is converted from ng to µg explicitly.

CFU/µg is a protocol-conditional normalization, not the proportion of cells transformed.

Plate estimates can disagree

Count sampling, mixing, plating, viability and background can produce different normalized estimates.

The workbench reports every plate and a simple arithmetic mean without deciding exclusions or uncertainty.

Follow the numbers

Normalize one diluted plate

  1. Convert the entered DNA mass from ng to µg.
  2. Multiply colonies by the cumulative dilution fold.
  3. Scale from plated volume to the full recovered volume.
  4. Divide estimated transformants by transformed DNA mass.

The CFU/µg value belongs to the complete entered protocol and plate observation.

Quick guide

How to use this calculator

  1. Enter the DNA mass added to the transformation and the final recovered suspension volume.
  2. For each plate, enter its observed colonies, cumulative pre-plating dilution fold and actual plated volume.
  3. Compare normalized plate estimates and retain protocol, control, background and countability evidence separately.

Calculation method

Calculation and interpretation

Expose the full plated-fraction denominator and technical-plate aggregation without treating colony yield as a universal cell property or correcting for viability, background and protocol differences.

Estimated total transformants = colonies×dilution fold×recovery volume/plated volume; plate TE = estimated total transformants/DNA mass(µg).

Worked example

Normalize one diluted plate

The CFU/µg value belongs to the complete entered protocol and plate observation.

Estimated total transformants = colonies×dilution fold×recovery volume/plated volume; plate TE = estimated total transformants/DNA mass(µg).

Supported inputs

Precision and limits

Selective colonies are entered observations

Background, satellite colonies, merged colonies, contamination and countability are not inferred.

Homogeneous recovery assumed

The plated aliquot is treated as representative of the final recovered suspension.

No viability denominator

CFU/µg is not percent transformed and does not divide by viable recipient cells.

Protocol conditional

Cell strain, DNA topology and purity, recovery, selection and handling affect comparisons.

Simple technical mean

Plate estimates are averaged equally; the workbench does not choose exclusions, weights or confidence intervals.

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