1. In vitro differentiation of germ cells from nonobstructive azoospermic patients using three-dimensional culture in a collagen gel matrix 
Jae-Ho Lee, Ph.D., Myung C. Gye, Ph.D., Kyoo Wan Choi, Ph.D., Jae Yup Hong, M.D., Ph.D., Yong Bok Lee, M.D., Dong-Wook Park, Ph.D., Seung Jae Lee, M.D., Churl K. Min, Ph.D. 
Fertility and Sterility 
Volume 87, Issue 4, Pages (April 2007)
DOI: /j.fertnstert
Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions

2. FIGURE 1
Histologic examinations of testicular biopsy samples from men with nonobstructive azoospermia. Fresh testicular biopsy samples from 18 patients with nonobstructive azoospermia were taken for histologic examinations by the hematoxylin and eosin (H & E) staining method (A, B) or by immunostaining with anti-PRM2 antibodies (C, D). A and C represent a testicular tissue of spermatogenic arrest, whereas B and D represent a normal spermatogenic tissue. The arrow in D indicates PRM2-positive cells. Magnification, ×400.
Lee. Three-dimensional culture of spermatogenic cells. Fertil Steril 2007.
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions

3. FIGURE 2
Photographs of a collagen gel matrix and testicular cells within the collagen gel mixture before and after culture in vitro. Testicular cells prepared from testicular biopsy tissues were mixed with a collagen-rich solution that was previously isolated from rat tails according to the methods described in the Materials and Methods section. The resulting cell–collagen mixture was solidified and cultured in the culture medium at 32°C for 12 days. The overall morphologies of the solidified collagen gel matrix before and after 12 days in culture are compared in A and B, respectively, whereas testicular cells in the gel mixture before and after 12 days in culture are shown in C and D, respectively. Magnification in C and D, ×200.
Lee. Three-dimensional culture of spermatogenic cells. Fertil Steril 2007.
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions

4. FIGURE 3
Morphological and immunohistologic analyses of testicular cells before and after culture in vitro. Testicular cells were photographed before (A, C) and after (B, D) 12 days in culture at magnification ×200 (A, B) and ×400 (C, D). Arrows in A to D indicate primary spermatocyte (PS) and round spermatid (RS). Testicular cells were photographed after immunostaining with anti-PRM2 antibody before (E) and after (F) 12 days in culture at magnification ×200. Arrows in F indicate PRM2-positive cells. Testicular cells were immunostained with preimmune serum as a control and photographed at magnification ×200 (G).
Lee. Three-dimensional culture of spermatogenic cells. Fertil Steril 2007.
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions

5. FIGURE 4
Flow cytometric analysis of the DNA content in testicular cells. Testicular cells were analyzed flow cytometrically after propidium iodide staining based on the nuclear DNA content. Histograms represent results of FACS analysis of a representative testicular cell suspension obtained from a normal man (A), from groups with high meiotic differentiation rate before and after 12 days in culture (B), from groups with medium differentiation rate (C), and from groups with low differentiation rate (D). 1C = haploid cells; 2C = diploid cells; 4C = tetraploid cells.
Lee. Three-dimensional culture of spermatogenic cells. Fertil Steril 2007.
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions

6. FIGURE 5
Relationship between the serum FSH level and the in vitro meiotic differentiation rate. The level of serum FSH of nonobstructive azoospermic men was measured by RIA as described in the Materials and Methods section. In vitro meiotic differentiation rate was calculated as the percentage of the haploid cell population emerging after 12 days in culture. *P<.05, each compared with patients nos. 1 through 6.
Lee. Three-dimensional culture of spermatogenic cells. Fertil Steril 2007.
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions