Targeting of ES cells by peptide-conjugated quantum dots.

(A) Scheme of the peptide-conjugated quantum dots. (B) Bright-field and fluorescence microscopy of APWHLSSQYSRT peptide-conjugated quantum dots targeting ES cells. Dashed circle shows an ES cell colony. The fluorescence signal of peptide-conjugated quantum dots is shown in red and cell nuclei are shown in blue (Hoechest 33258). PMEF cells and quantum dots without conjugation of peptides were set as the controls. Scale bar, 100 µm. (C) Fluorescence microscopy of APWHLSSQYSRT peptide-conjugated quantum dots with mouse ES (mES) cells. The binding of APWHLSSQYSRT peptide-conjugated quantum dots to mES cells were undetectable. Free quantum dots without conjugation of peptides were set as the control. Scale bar, 100 µm.