Schematics of labeling efficiency analysis platform. For characterization of tag binders, CD86 served as a membrane anchor to localize target proteins to the intracellular side of the plasma membrane. ALFA-tag and tag of interest were inserted at the N- and C-terminus, respectively. Target and reference binders were separated by a distinct lateral offset distance doff. ALFA-tag nanobody (magenta) served as a reference to determine the labeling efficiency of target tag binder (for example, GFP-1H1 nanobody, cyan).
