Background: Isolation of motile sperm is essential for routine IVF programs.One of most important source of sperm for IVF is isolation of epididymal sperm (ESP).The problem regarding use of ESP is somatic cells which are recovered through sperm collection. The swim up and the swim down procedures are use to isolate motile sperm. The aim of the present study was to compare swim up and HISTOPREP®continuous gradient (HP) for isolation of ram ESP.Materials and Methods: Ram testes epididymes were collected from local slaughterhouse and transported to the Lab. Basic medium for separation of sperms from epididymis was caffeine treated BO solution. HISTOPREP was provided from the company. After incubating of cauda epididymis in the basic medium for 15 minutes, primary sperm parameters including sperm motility and concentration were recorded. Two equal volumes of sperm solution were use in swim up solution and on HISTOPREP gradient. We followed the routine swim up procedure by incubation of 800 ml of BO-caff in CO2 incubator for 30-45 minutes. For HISTOPREP, we followed the company protocol for isolation of human lymphocytes.After sperm recovery in two procedures, the secondary sperm parameters were recorded. To find the effects of the procedure on sperm parameters, proportion of secondary to primary sperm parameters, for each method, was calculated.Results: The results showed that proportion of motile sperms were 1.094±0.04 and 1.19±0.06 in HISTOPREP and swim up respectively (p>0.05). The proportion of secondary to primary sperm count for two procedure was similar (0.27±0.05 and 0.25±0.07 for HISTOPREP and swim up, respectively).Conclusion: The results showed that HISTOPREP and swim up have similar effects on motile sperm isolation for ram ESP.

Background: Motile sperm is essential for successful embryo production. The aim of the present study was to compare the in vitro embryo development following isolation of Ram epididymal sperm isolation by swim up (SP) or HISTOPREP® continuous gradient (HP).Materials and Methods: Ram testes-epididymis were provided from the local slaughterhouse and transported to the lab. Sperms were recovered from cauda epididymis and submitted to swim up or HP procedure for motile sperm isolation.Ewe ovaries were collected from sloutherhouse and their oocytes were picked up and transferred to TCM199 supplemneted with 10% FCS, 10% BFF and 3 IU hCG and 1 IU Merional (LH/FSH).After 22 hrs of incubation in 5% CO2 and 95% RH, submitted to IVF with sperms of both groups (total cultured oocyte numbers for HP and SP were 166 and 148) which were capacitized in BO medium. Embryo development was followed by incubation in TCM199 supplemented with 5 and 10% of FCS for cleavage and blastocyst formation and embryo development was evaluated at das 3 and 6 post insemination.Results: The results showed similar efficacy of both procedures for Ewe IVF in cleavage rate (54.6 and 55.6% for HP and SP respectively). Blastocyst rate also was similar between groups (5.6 and 3% for HP and SP, respectively).The low rate of blastocyst in this project may return to our embryo culture medium.Conclusion: HP may have similar efficacy to SP for producing in vitro Ewe embryo.