Figure 1.

Nanoparticle-labeled endometrial stromal cells. Qtracker® label of endometrial stromal cells. Quantitation of nanoparticle-labeled endometrial stromal cells (A) with different duration of chase (n = 4 per time point) and (B) at different menstrual phases (n = 3, proliferative, white; n = 3, secretory, black). Fluorescence expressing cells are reported as means ± SEM of the percentage of total stromal cells seeded. Day 1 post-labeled stromal cells stained with DAPI nuclei stain (blue) indicating the nanoparticles (red) are located in the cytoplasm (C). Representative phase contrast images of nanoparticle-labeled stromal cells at different days in culture (D – H). Nanoparticle-labeled cells (arrows) detected on day 1 (D) and then among the unlabeled stromal cells on day 3 (E), day 6 (F) and day 15 (G). Fluorescent signal retained at day 21 (H) (E - H). Negative controls of unlabeled stromal cells are shown in the insets. Representative photographs of post-labeled day 21 endometrial stromal cells after FACS analysis as FPC (I) and non-FPC (J) population in culture for five days. Culture dish displaying distribution of stromal colony forming units (CFU) (K) after 15 days of culture. Morphology of large (L) and small (M) CFU. Scale bars = 50 μm (C, I, J) and 100 μm (D - H, L - M). DAPI, 4',6-diamidino-2-phenylindole; FACS, fluorescence-activated cell sorting; SEM, standard error of the mean.