Fig. 1.
Comparison between traditional non-selectable genetic markers (left) and antibiotic resistance markers (right) in the context of microinjection. When visual phenotypic markers are used for nematode transgenesis by microinjection, transgenic F1 worms need to be screened and isolated by hand by an experimentalist (left), while antibiotic selection offers the possibility of hands-off selection and maintenance of stable transgenic lines (right). In the case of antibiotic resistance markers, F1 isolation by hand ensures clonal homogeneity of isolated strains, but further maintenance can be done by chunking without further visual screening as long as the animals are kept on antibiotic-containing medium. *In the presence of antibiotic, wild-type larvae are unable to develop and die after a few days