A dextran swim-up procedure for separation of highly motile and viable ram spermatozoa from seminal plasma

doi:10.1016/0093-691X(96)00149-5

Theriogenology

Volume 46, Issue 1, July 1996, Pages 141-151

https://doi.org/10.1016/0093-691X(96)00149-5 Get rights and content

Abstract

Although washing of sperm cells by centrifugation is a procedure in widespread use, there have been indications that centrifugation may be harmful to the cells. The objective of this study was to develop a modified swim-up technique, without centrifugation, to get a selection of highly motile and viable ram spermatozoa free of semen plasma.

Semen collected from 3 rams over a period of a year was pooled into a low, medium and high motility group, and aliquots from each pool were placed beneath a dextran solution and overlaid with medium. The top layer of the medium was collected (and replenished) 4 times at 15-min intervals. Evaluated were the pre- and post-swim-up progressive individual motility, membrane integrity and resistance to a hypoosmotic swelling test (HOS). Semen samples with initial motility < 60% showed the highest relative improvement in all 3 parameters; samples with 65 to 70 and > 70% initial motility improved less but showed final absolute values similar to those in the low motility group and to each other. The first swim-up layer had the highest contamination with semen plasma (17% beta-N-acetylglucosaminidase (NAG), 13% citric acid content) and the lowest motility score. The second, third and fourth fractions were pooled and showed low plasma contamination (2% NAG and 5% citrate), 80% motility, 70% HOS, and 72% viability, up from the pre-swim-up values of 68, 66 and 59%, respectively. Our data suggest that the dextran swim-up procedure is suitable for evaluating ram spermatozoa for in vitro and in vivo procedures in assisted reproduction.

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Citation Excerpt :
The filtration, however, is believed to be based on the fact that non-viable sperm tend to adhere to the Sephadex matrix to a greater extent than motile and seemingly functional sperm, and the latter are able to cross the filtration barrier without modification of functional characteristics (Bussalleu et al., 2008). For ram semen, a number of sperm selection methods have been tried, including Sephadex filtration (see above), swim-up methods (García-López et al., 1996), sucrose washing, and Millipore filtration (Marti et al., 2006), as well as Percoll density gradient centrifugation (DGC) (Valcárcel et al., 1996). Even though there have been great advances in DGC procedures for sperm selection with different species (Santiago-Moreno et al., 2014, 2016), these procedures include centrifugal forces that may be harmful, especially for ram sperm (García-López et al., 1996).
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However, the standard swim-up procedure involves centrifugation steps that induce a decline in the motility of spermatozoa (Alvarez et al., 1993). A swim-up method, without centrifugation, was developed by García-López et al. (1996) for the isolation of motile and highly viable ram spermatozoa. In order to optimize those results, an alternative procedure was developed by Dorado et al. (2016) for dog sperm selection before cooling using a column of colloid between the semen sample and the migration medium.
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A dextran swim-up procedure for separation of highly motile and viable ram spermatozoa from seminal plasma

Abstract

J Equine Vet Sci

Fertil Steril

Theriogenology

Theriogenology

Fertil Steril

Fertil Steril

Fertil Steril

Clin Chem Acta

Cryobiology

Fertil Steril

Theriogenology

Significance of reactive oxygen species and antioxidants in defining the efficacy of sperm preparation techniques

J Androl

Centrifugation of human spermatozoa induces sublethal damage; separation of human spermatozoa from seminal plasma by a dextran swim-up procedure without centrifugation extends their motile lifetime

Human Reprod

Survival of ram spermatozoa at high dilution: Protective effect of simple constituents of culture media as compared with seminal plasma

Reprod Fertil Dev

Effect of sperm motility on in vitro fertilization

Arch Androl

Poor hypo-osmotic swelling test results from cryopreserved sperm despite preservation of sperm motility

Arch Androl

Detrimental effects of cryopreservation on the structural and functional integrity of the sperm membrane

Arch Androl