To increase the number of transformants, prior to transformation, ligations were precipitated with yeast tRNA [58].
Transformation efficiency (number of transformants/µg of plasmid) for low, medium and large sized amplification products.
The total number of transformants isolated directly after the transformation with the codon-optimized gene was 60, yet many failed to grow or sporulate in the isolation process for single progeny.
Transformation rates represent the number of transformants obtained per viable cell for 1 µg of DNA.
Control transformations of linearized plasmid DNA alone or PCR amplicons alone did not yield a significant number of transformants (< 20) while the 'complete' transformation contained several hundred transformants (data not shown).
The frequency of transformation was determined by calculating the number of transformants for a given amount of viable cells (5×108 bacteria) with 1 µg DNA of the suicide plasmid (pILL796).
Aliquots were taken after transformation to determine the total number of transformants, and after freezing, to determine the titer.
The frequency of transformation was calculated as the ratio between the number of transformants that exhibited both antibiotic resistance and the correct aphVIII fragment following PCR and the total number of cells used for each transformation experiment (9 × 10 cells).
