Preparation and incubation conditions affect the DNA integrity of ejaculated human spermatozoa

Abstract

Appropriate semen processing and assessment are critical for successful infertility treatment. We investigated whether laboratory procedures including semen preparation and incubation affect sperm DNA integrity. A total of 153 infertile men were involved. Conventional semen parameters and sperm chromatin structure assay (SCSA) parameters, that is, DNA fragmentation index (%DFI) and high DNA stainability (%HDS), were assessed on the fresh ejaculated semen samples, which were treated and incubated under different conditions. Negative correlations were identified between the %DFI and sperm concentration, motility, progressive motility and morphology. A lower percentage of DFI was detected in spermatozoa when density gradient centrifugation (DGC) was followed by swimup treatment in comparison with DGC alone (P < 0.01). Although the %DFI increased in a time-dependent manner with incubation both at room temperature (RT) and at 37ºC in air, the %DFI after 24 h at RT was significantly lower than that at 37ºC (P < 0.05). Incubation with 5% CO2 was effective in maintaining sperm motility (P < 0.01); however, it induced further elevation of %DFI (P < 0.001). Thus, sperm DNA damage was associated with longer incubation periods. Interestingly, common culture conditions, such as maintaining pH and temperature, compromised the sperm DNA integrity.

Cryopreservation of a small number of human sperm using enzymatically fabricated, hollow hyaluronan microcapsules handled by conventional ICSI procedures

“…performed using a small number of sperm, it takes a much longer time until sperm injection, causing the accumulation of reactive oxygen species [3,4]. Such changes in culture conditions have been shown to be involved in the lipid peroxidation of cell membranes, nuclear DNA fragmentation, and delay of embryo development [5][6][7][8]. Several groups have reported the cryopreservation of a small number of sperm using devices for embryo vitrification [9,10] by embedding them into an alginate gel [11] and by injecting them into an empty zona pellucida (ZP) [12][13][14].…”

Influence of temperature and sperm preparation on the quality of spermatozoa

“…It is well known that the testis temperature is approximately 2-3°C below body temperature (Elder and Dale, 2011), as this is required for the production and maintenance of viable spermatozoa (Appell et al, 1977;Setchell, 1998). Despite the numerous articles published on the harmful effects of long-term in-vitro sperm incubation at body temperature, it is still current practice in most IVF laboratories to store prepared sperm samples at this unfavourable temperature prior to their use in assisted reproduction treatment (Matsuura et al, 2010).…”

“…The quality of the sperm sample is influenced by various laboratory factors, including: (i) use of different sperm preparation techniques (Boomsma et al, 2007;Chen and Bongso, 1999;Marchesi et al, 2010); (ii) temperature during sperm preparation (Franken et al, 2011;Otsuki et al, 2008); (iii) time interval from sperm preparation to IUI (Yavas and Selub, 2004); and (iv) temperature during long-term in-vitro incubation of prepared sperm samples (Aitken et al, 1996;Makler et al, 1981;Matsuura et al, 2010;Petrella et al, 2003). It is well known that the testis temperature is approximately 2-3°C below body temperature (Elder and Dale, 2011), as this is required for the production and maintenance of viable spermatozoa (Appell et al, 1977;Setchell, 1998).…”

DNA integrity in fresh, chilled and frozen-thawed canine spermatozoa

“…One of the most commonly reported is sperm processing, especially centrifugation and incubation (Bungum et al 2008;Koderle et al 2009;Matsuura et al 2010). Another potential factor is the use of different types of extenders (Shahiduzzaman and Linde-Forsberg 2007;Fernandez-Santos et al 2009;Morrell et al 2009).…”