Table 1.
Overview of the various types of Nb libraries with their specifications, the Nb selection, the primary and secondary features of the identified Nb and a list of possible applications where Nbs might make a difference.
| Nb library | |
| Immune | Start with blood of an immunised camelid |
| Multiple libraries will be needed for various projects | |
| (Relatively) Small library size (106–108) | |
| Affinity‐matured Nbs will be obtained | |
| (Relative) high titre of target‐specific binders | |
| Naïve | Immunisation is avoided (no adverse effect from toxic targets) |
| Works for nonimmunogenic targets as well | |
| Very large library size (109–1011) is needed | |
| One library serves for multiple projects | |
| Nbs might require stability/affinity improvement | |
| Synthetic | Immunisation is omitted (no adverse effect from toxic targets) |
| Works for nonimmunogenic targets as well | |
| Extremely large library size (109–1015) is required | |
| One library serves for multiple projects | |
| Nbs might require stability/affinity improvement | |
| Nb selection | |
| Phage display | Robust, fast, many selection tricks, versatile |
| Yeast display | Highly selective, FACS gating for special function |
| Bacterial display | Sporadically used |
| Two hybrid | Bacterial or yeast, sporadically used |
| Ribosome display | In vitro technique, sporadically used for Nbs |
| CIS display | In vitro technique, sporadically used |
| Deep sequencing | Sporadically used |
| Phenotypic selection | Highly promising for selecting function modulating Nbs |
| NestLink based selection | Amenable to sophisticated screenings, for example panning in organisms |
| Nb properties | |
| Primary features | Secondary features |
| Small size/low MW | Fast blood clearance |
| Economic production | Deep penetration in tissues |
| High specificity | Enzyme modulating |
| High affinity | Low immunogenicity (well tolerated and nontoxic) |
| Robust | Long shelf life |
| Monomeric | High solubility |
| Easy engineering | Directional immobilisation |
| Genetically encodable | Can be splitted and integrated in other protein scaffolds |
| Nb applications | |
| Research | Target crystallisation chaperon |
| Superresolution microscopy tool | |
| Intracellular expression/intrabodies | |
| Intracellular target tracing; interference with endogenous target | |
| Interference with in vivo function of endogenous Ag | |
| Developmental biology | |
| Manifold constructs (bivalent/biparatopic/multivalent/bispecific) | |
| In vitro diagnostic | Lateral flow assays |
| Electrochemical Ag detection | |
| In vivo diagnostic | Noninvasive in vivo imaging |
| Therapy | Autoimmune disease and inflammation |
| Cancer | |
| Infectious diseases | |
| Envenoming | |
| Immuno‐pheresis | |
| (Agro‐)Biotech | Immuno‐adsorbents |
| Protection of plants against pathogens | |
| Animal feeding | |