Figure 4.

Biotin conjugation of PIC5a–f for grafting PIC brushes to streptavidin beads. (a) Schematic representation of the two-step binding protocol of the allyl polymers using tetrazole-PEG₈-biotin. (b) Fluorescence intensity at λ = 415 nm of the conjugated biotin of PIC5a–f after reaction with an excess of tetrazole-PEG₈-biotin. (c) Fluorescence intensity at λ = 415 nm of PIC5b when reacted with different equivalents of tetrazole-PEG₈-biotin per allyl. (d) Binding of the biotinylated PIC5a–f (labeled with Alexa Fluor 647) to streptavidin-functionalized beads as measured by the mean fluorescence intensity of the beads by flow cytometry. (e) Binding of the biotinylated PIC5b from (c) (labeled with Alexa Fluor 647) to streptavidin-functionalized beads as measured by the mean fluorescence intensity of the beads by flow cytometry. Values plotted are mean ± standard deviation of three independent experiments.