Figure 7.

GFP can be trafficked into neurons with CL4. GFP with a histidine tag (His₆) can be conjugated to CL4 dots and trafficked into neurons. (a) GFP-His₆ CL4 dots were applied for 24 hr and show similar distribution in CA3 region of hippocampus as previously described for JB577-CL4 QDs (Walters et al., 2012). (b) GFP-His₆ without CL4 shows very little uptake in the same slices when applied for the same time period. This shows that CL4 QDs can be used to traffic large proteins (32.7 kDa) such as GFP. (c) Quantification of green channel fluorescence around the CA3 region of the hippocampus following application of GFP shows that cells treated with GFP conjugated to CL4 through His₆ show significantly increased trafficking into neurons compared with GFP alone (Student’s independent t test: p < .005). Red represents QDs, green is eGFP-His₆, and blue is DAPI. GFP = green fluorescent protein; CL = compact ligand; QDs = quantum dots; DAPI = 6-diamidino-2-phenylindole.