No reaction was observed when the primary antibody was omitted. anti-testis proteins, specifically to target Hsf5, and can be useful as a scientific tool to investigate the critical genes in the development and spermatogenesis. Key Words: Antibody, Development, Hsf5, Hybridoma, Spermatogenesis Introduction Heat 20(R)-Ginsenoside Rh2 shock factors (Hsfs), as transcription 20(R)-Ginsenoside Rh2 factors, play important roles in development and gametogenesis. Hsf family (Hsf 1-5) has been characterized from vertebrates that regulate responses to environmental stimuli (1-3). The fifth member of the Heat shock factor family (Hsf5) is important in fertility, especially in males (4). Hsf5 is essential for progression of meiotic prophase 1 during spermatogenesis so that hsf5-/- mutants are infertile because of gonadal misregulation of several genes (5). On the other hand, monoclonal antibody preparation is a useful method for detecting the proteins specifically. Prior to this study, Hsf5, including Hsf1, Hsf2, Hsf4, and Hsf5 have been isolated and characterized from zebrafish. Hsf5 is one of the most important genes that have been selected as suggested by several 20(R)-Ginsenoside Rh2 molecular techniques, though detailed functional characterization of Hsf5 has not been performed in mice (6). Therefore, preparation of anti-Hsf5 monoclonal antibody can be effective in the investigation, prevention, and treatment of experimental male infertility. Here, we decided to prepare a specific monoclonal antibody-based hybridoma technology for detection and characterization of Hsf5 in mice. In our laboratory, we have produced and characterized an anti-testis monoclonal antibody. By bioinformatics analysis, we could select 20(R)-Ginsenoside Rh2 several testis-specific proteins that are probably targets of the desired monoclonal antibody (mAb10C3). Materials and Methods Experimental animals Balb/C mice were from Tehran University or college of Medical Sciences, Iran, and managed under a controlled light cycle (14 L: 10 D). Testes were removed from mice in the age groups of 7 and 21 days and 6-8 weeks, rapidly freezing on dry snow and then kept at -80 C until use. Notably, the treatment of animals was carried out in accordance with the Guiding Principles for the Care and Use of Study Animals promulgated from the Society for the Study of Reproduction (7). Generation and screening of the anti-testis monoclonal antibody Antibody preparation was performed by cell fusion and hybridoma technology. Hybridoma clones were produced by fusion of SP2/0 cell collection and immunized spleen cells of mice. The immunization process of mice was performed five instances with 2-week intervals by intraperitoneal injection of the desired antigen (lysates of mice testes) that mixed with Freunds adjuvant (8, 9). Screening of antibody titer produced by hybridoma clones was performed by indirect 20(R)-Ginsenoside Rh2 ELISA and finally F11R the clone with the highest OD value was selected as the stable hybridoma, called 10C3 clone. The specificity of the antibody produced by hybridoma clone (mAb10C3) was determined by several histological and molecular techniques. The characterization of mAb10C3 was performed within the sperm and testis of mice by immunocytochemistry and immunohistochemistry techniques. In addition, Western blot analysis were performed to determine the size of probable protein(s) that may be target of the produced mAb10C3 (all the protocols have been explained in our previously published text) (10). Bioinformatics analysis According to the results of Western blot analysis, mAb10C3 could specifically identify the mouse testes and sperm proteins that have molecular weights about 53 and 73 KDa, in comparison with other cells lysates that did not show any band in Western blot. Therefore, our results possess suggested that mAb10C3 were specifically prepared against mouse testis antigens. By these data in our earlier research, we investigated the most probable target genes of generated mAb on UniGene part of NCBI. As we mentioned previously, Hsf5 was one of the genes that may be the prospective of desired mAb. Accordingly, we proposed that mAb10C3 was specifically designated against Hsf5 and decided to investigate this proposal here. Data analysis of monoclonal antibody 10C3 as the hsf5 marker Hsf5 is one of the most important proteins that is specific target of mAb10C3. So here, we investigated how mAb10C3 could act as anti-Hsf5 antibody within the testis cells of mice. In.