Gene-deletion mutants were selected after transfection with a single PlasmoGEM vector (PbGEM-065291), indicating that PBANKA_144560 is not essential for blood stages. However, gene deletion mutants could not be obtained by cloning.

In this study also evidence was found for successful gene deletion as determined by barcode PCR in a large pool of gene-deletion mutants.

Evidence is provided for (stronly) reduced fitness (growth rate) of blood stages

In this study P. berghei blood stages were transfected with a large pool of barcoded disruption (gene-deletion) vectors. These disruption vectors contained long modification arms to efficiently target the genes of interest.
In addition the vectors contain gene-specific molecular barcodes. Co-transfecting multiple gene-deletion vectors in the same electroporation reproducibly generates complex pools of barcoded P. berghei mutants.
In this study parasites were (mainly) transfected with a pool of vectors targeting protein kinase genes for deletion.
Unsuccessful gene disruption/deletion or successful gene disruption/deletion is determined by the absence or presence of the barcode in the population (as determined by barcode-specific PCR analysis).

To analyze growth curves derived from barcode counting two parameters were considered: (1) the relative abundance of each barcode within the pool, and (2) the relative fitness of each mutant, i.e., the rate at which its abundance changed each day (i.e. growth rate).