In search of an improved injection technique for the clinical application of spermatogonial stem cell transplantation  Katrien Faes, Tony Lahoutte, Anne Hoorens, Herman Tournaye, Ellen Goossens  Reproductive BioMedicine Online  Volume 34, Issue 3, Pages 291-297 (March 2017) DOI: 10.1016/j.rbmo.2016.12.007 Copyright © 2016 Reproductive Healthcare Ltd. Terms and Conditions

Figure 1 Histology and immunohistochemistry stainings. A) Presence of GFP+ cells (brown cells) in the seminiferous tubules (Scale bar = 100 µm). B) Presence of GFP+ cells in the interstitium (brown cells, indicated by black arrows, Scale bar = 100 µm)). GFP+ mouse testicular tissue was used as positive control (PC; Scale bar = 200 µm). GFP+ mouse testicular tissue was used as negative control (NC; Scale bar = 200 µm). C-D) Comparison of GFP+ after hydrostatic injection of a 1400 µl cells/ml cell suspension at 50 cm above the testis and after injection of a 1400 µl, 2600 µl and 3000 µl cells/ml suspension with the infusion pump. C) Proportion of interstitium filled with GFP+ cells. No significant difference was observed. D) Overall scope of GFP+ cells found in the whole injected testes. The proportion of interstitium containing GFP+ cells differed significantly (* P = 0.020 by Mann Witney U-test) between the 50 cm height and 1400 µl pump groups. All data presented as mean ± SD. GFP = green fluorescent protein. Reproductive BioMedicine Online 2017 34, 291-297DOI: (10.1016/j.rbmo.2016.12.007) Copyright © 2016 Reproductive Healthcare Ltd. Terms and Conditions

Figure 2 Single-photon emission computed tomography (SPECT) analysis. SPECT images acquired after injection of 1400 µl of a 10 million cells/ml suspension under hydrostatic pressure, provided by placing a water reservoir at 50 cm above the testis (A) or after injection of different volumes (B: 1400 µl; C: 2600 µl; D: 3000 µl) of a 10 million cells/ml suspension with an infusion pump. The pictures shown are representative for the different conditions tested. Reproductive BioMedicine Online 2017 34, 291-297DOI: (10.1016/j.rbmo.2016.12.007) Copyright © 2016 Reproductive Healthcare Ltd. Terms and Conditions