Fig. 1

Library construction, expression, and purification of CD105 nanobody. a, b The VHH genes were obtained by two steps PCR. c The library size was measured by counting the colonies number after serial dilution. d Twenty-four colonies were randomly picked to estimate the correct insertion rate of VHH genes by PCR amplification. e SDS-PAGE analysis of purified CD105-specific nanobodies. f Properties of CD105-specific nanobodies. The affinity of these nanobodies was determined by Biacore. Theoretical isoelectric point (pI), molecular weight (Mw), and extinction coefficient (ε) were calculated by the ExPAsy ProtParam Tool