Scenario
You plated transformed cells and counted colonies from one or more dilutions.
The goal is to connect the colony count to the actual DNA input and recovery volume rather than reporting a vague success or failure.
Inputs to confirm
DNA mass added to the competent cells.
Final recovery volume, plated fraction, and any dilution before plating.
Whether the plate came from a ligation product or a positive-control plasmid.
How a researcher would use the result
Use the calculated efficiency to separate a weak ligation from a weak competent-cell batch.
Compare the ligation outcome to a control transformation rather than diagnosing from one number alone.
Common failure points
Forgetting to scale for the plated fraction.
Reporting colony count without the DNA input basis.
Comparing ligation and control plates that did not use comparable recovery and plating conditions.