RPS19 and cyst: However when we quantified DBA+ cyst formation (indicated by DBA staining surrounding the entire circumference of the vacuole) in two endogenously tagged clones from the same transfection we found that the C-terminal tag significantly reduced BIC-driven DBA+ cyst formation (tagged strains switched at a frequency of <10% compared to over 70% in the wild type parent; P ≤ 0.0001 for both clones).