Modulation of cell-surface NRP1 by polysaccharides and poly- and oligonucleotides. HUVECs were incubated at 37°C for 1 hour with the indicated compounds (each tested at 0, 1, 8, 64 μg/mL); after incubation, NRP1 was detected by flow cytometry. Compounds tested in (A) dextran, 500-kDa dextran sulfate (DS500), alginic acid (alginic a.), carboxymethylcellulose (carbo. cell), pectin, mannan, inulin, cellulose sulfate (cell. sul), carrageenan λ IV (car. λ IV), poly-l-Glu acid (p-lGlu), and poly-d-Glu acid (p-dGlu); in (B) polyribonucleotides poly A, poly G, and poly C; oligodeoxyribonucleotides T18, G18, C18, G6; phosphorothioate oligodeoxyribonucleotides sA18, sT18, sG18, sC18, and dGMT. Results reflect the relative mean fluorescence intensities with and without compounds.