Live A431 cells were incubated with anti-human EGFR (Cetuximab biosimilar) followed by Nano-Secondary® alpaca anti-human IgG, recombinant VHH, CoraLite® Plus 647 [CTK0117] (magenta, shuGCL647-2 ). Cells were fixed and nuclei were stained with DAPI (blue). Epifluorescence images were acquired with a 40x objective and post-processed.

Immunofluorescence analysis of transgenic CHO-TIM3 cells. PFA-fixed cells were stained with anti-human TIM3 (Cobolimab biosimilar), Nano-Secondary® alpaca anti-human IgG, recombinant VHH, CoraLite® Plus 647 [CTK0117] (gray) and DAPI (blue).

Flow cytometry analysis of 1X10^6 human peripheral blood mononuclear cells (PBMCs) stained with anti-human CD20 ( Rituximab biosimilar) and Nano-Secondary® alpaca anti-human IgG, recombinant VHH, CoraLite® Plus 647 [CTK0117) (shuGCL647-2). Cells were co-stained with CoraLite® Plus 488 conjugated anti-human CD19 antibody.

Dot blot assay demonstrates that anti-human IgG Nano-Secondary (CTK0117) has no cross-reactivity to human IgA/IgM/IgE, and goat, guinea pig, mouse, rabbit, rat, and sheep serum. It shows slight cross-reactivity to macaque serum.

Schematic representation of anti-human IgG Nano-Secondary binding to its target. Human IgG primary antibody (blue) is bound with two identical monoclonal human IgG Fc- specific Nanobody molecules (green). In total, 4 fluorophores (red stars) label the human IgG primary antibody.