Uptake of fluorescently labelled oligonucleotides from culture medium by B. pahangi. Uptake of small RNAs from media was assessed after 24–48 hours of culture using 0.5 μM Cy3-labelled siRNA. Panels A-D show mosquito-derived L3 after 48 hours (scale bar represents 100 μm in A&B and 25 μm in C&D). Panels E & F show uptake in day 5 p.i. L3 after 24 hours (scale bar 25 μm). No fluorescence was observed in controls cultured in the absence of Cy3-labelled siRNA (not shown).