The Experts below are selected from a list of 222 Experts worldwide ranked by ideXlab platform
Heriberto Rodriguezmartinez - One of the best experts on this subject based on the ideXlab platform.
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comparison of density gradient and single layer Centrifugation of stallion spermatozoa yield motility and survival
Equine Veterinary Journal, 2009Co-Authors: J M Morrell, A M Dalin, Heriberto RodriguezmartinezAbstract:Summary Reasons for performing study: A new, simpler, technique of colloidal Centrifugation has recently been developed, designated single layer Centrifugation (SLC). This technique requires evaluation by comparison with a density gradient for its ability to select the best quality spermatozoa and its practicality of use on studfarms. Objective: To compare the effect of 2 methods of colloidal Centrifugation, density gradient Centrifugation and single layer Centrifugation, on stallion sperm motility, yield and survival, using freshly collected extended stallion semen. Methods: Aliquots of extended stallion semen from 10 stallions (38 ejaculates) were processed by the 2 methods of colloidal Centrifugation. For both uncentrifuged and centrifuged samples, sperm yield was calculated and subjective sperm motility assessed over several days to provide an estimate of sperm survival. Some stored semen samples, held at 4°C overnight, were also available for testing. Results: For fresh, extended semen, a similar recovery yield of motile spermatozoa was seen for the 2 methods of preparation for single layers and density gradients, respectively. Sperm motility and survival rate were significantly improved by colloidal Centrifugation compared to unprocessed ejaculate, without any significant difference between methods (SLC vs. gradient). However, the yield was reduced by 18–20% when cold-stored semen was used for Centrifugation compared to fresh semen; and more variation between ejaculates was observed than for fresh ejaculates. Again, sperm motility and sperm survival were improved in the centrifuged sperm preparations compared to stored, unprocessed ejaculates. Potential relevance: The 2 colloid Centrifugation techniques produce equivalent sperm preparations in terms of sperm quality. However, the SLC method would be more practical and convenient for use in the field.
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prolongation of stallion sperm survival by Centrifugation through coated silica colloids a preliminary study
Animal reproduction, 2008Co-Authors: J M Morrell, A M Dalin, Heriberto RodriguezmartinezAbstract:Difficulties to be overcome in the widespread use of artificial insemination (AI) in mares are low sperm survival and poor sperm quality, which are encountered frequently among breeding stallions. Therefore, a method is needed to prolong the useable life of stallion spermatozoa destined for AI. In a preliminary study using 8 ejaculates from one stallion, density gradient Centrifugation or Centrifugation through a single layer of silica colloid appeared to prolong sperm motility compared to uncentrifuged spermatozoa, thereby potentially extending the useable life of treated stallion spermatozoa for AI. Furthermore, there was an improvement in sperm morphology, with the number of morphologically normal spermatozoa increasing from 42 to 60.5% and with the removal of approximately 60% spermatozoa with head or tail defects from the original population. No difference between the two Centrifugation methods, in terms of yield or duration of spontaneous motility, could be detected in this study. Either of these methods of colloidal Centrifugation could be a useful aid to preparing stallion spermatozoa for artificial breeding techniques, including AI.
J M Morrell - One of the best experts on this subject based on the ideXlab platform.
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comparison of density gradient and single layer Centrifugation of stallion spermatozoa yield motility and survival
Equine Veterinary Journal, 2009Co-Authors: J M Morrell, A M Dalin, Heriberto RodriguezmartinezAbstract:Summary Reasons for performing study: A new, simpler, technique of colloidal Centrifugation has recently been developed, designated single layer Centrifugation (SLC). This technique requires evaluation by comparison with a density gradient for its ability to select the best quality spermatozoa and its practicality of use on studfarms. Objective: To compare the effect of 2 methods of colloidal Centrifugation, density gradient Centrifugation and single layer Centrifugation, on stallion sperm motility, yield and survival, using freshly collected extended stallion semen. Methods: Aliquots of extended stallion semen from 10 stallions (38 ejaculates) were processed by the 2 methods of colloidal Centrifugation. For both uncentrifuged and centrifuged samples, sperm yield was calculated and subjective sperm motility assessed over several days to provide an estimate of sperm survival. Some stored semen samples, held at 4°C overnight, were also available for testing. Results: For fresh, extended semen, a similar recovery yield of motile spermatozoa was seen for the 2 methods of preparation for single layers and density gradients, respectively. Sperm motility and survival rate were significantly improved by colloidal Centrifugation compared to unprocessed ejaculate, without any significant difference between methods (SLC vs. gradient). However, the yield was reduced by 18–20% when cold-stored semen was used for Centrifugation compared to fresh semen; and more variation between ejaculates was observed than for fresh ejaculates. Again, sperm motility and sperm survival were improved in the centrifuged sperm preparations compared to stored, unprocessed ejaculates. Potential relevance: The 2 colloid Centrifugation techniques produce equivalent sperm preparations in terms of sperm quality. However, the SLC method would be more practical and convenient for use in the field.
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prolongation of stallion sperm survival by Centrifugation through coated silica colloids a preliminary study
Animal reproduction, 2008Co-Authors: J M Morrell, A M Dalin, Heriberto RodriguezmartinezAbstract:Difficulties to be overcome in the widespread use of artificial insemination (AI) in mares are low sperm survival and poor sperm quality, which are encountered frequently among breeding stallions. Therefore, a method is needed to prolong the useable life of stallion spermatozoa destined for AI. In a preliminary study using 8 ejaculates from one stallion, density gradient Centrifugation or Centrifugation through a single layer of silica colloid appeared to prolong sperm motility compared to uncentrifuged spermatozoa, thereby potentially extending the useable life of treated stallion spermatozoa for AI. Furthermore, there was an improvement in sperm morphology, with the number of morphologically normal spermatozoa increasing from 42 to 60.5% and with the removal of approximately 60% spermatozoa with head or tail defects from the original population. No difference between the two Centrifugation methods, in terms of yield or duration of spontaneous motility, could be detected in this study. Either of these methods of colloidal Centrifugation could be a useful aid to preparing stallion spermatozoa for artificial breeding techniques, including AI.
A M Dalin - One of the best experts on this subject based on the ideXlab platform.
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comparison of density gradient and single layer Centrifugation of stallion spermatozoa yield motility and survival
Equine Veterinary Journal, 2009Co-Authors: J M Morrell, A M Dalin, Heriberto RodriguezmartinezAbstract:Summary Reasons for performing study: A new, simpler, technique of colloidal Centrifugation has recently been developed, designated single layer Centrifugation (SLC). This technique requires evaluation by comparison with a density gradient for its ability to select the best quality spermatozoa and its practicality of use on studfarms. Objective: To compare the effect of 2 methods of colloidal Centrifugation, density gradient Centrifugation and single layer Centrifugation, on stallion sperm motility, yield and survival, using freshly collected extended stallion semen. Methods: Aliquots of extended stallion semen from 10 stallions (38 ejaculates) were processed by the 2 methods of colloidal Centrifugation. For both uncentrifuged and centrifuged samples, sperm yield was calculated and subjective sperm motility assessed over several days to provide an estimate of sperm survival. Some stored semen samples, held at 4°C overnight, were also available for testing. Results: For fresh, extended semen, a similar recovery yield of motile spermatozoa was seen for the 2 methods of preparation for single layers and density gradients, respectively. Sperm motility and survival rate were significantly improved by colloidal Centrifugation compared to unprocessed ejaculate, without any significant difference between methods (SLC vs. gradient). However, the yield was reduced by 18–20% when cold-stored semen was used for Centrifugation compared to fresh semen; and more variation between ejaculates was observed than for fresh ejaculates. Again, sperm motility and sperm survival were improved in the centrifuged sperm preparations compared to stored, unprocessed ejaculates. Potential relevance: The 2 colloid Centrifugation techniques produce equivalent sperm preparations in terms of sperm quality. However, the SLC method would be more practical and convenient for use in the field.
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prolongation of stallion sperm survival by Centrifugation through coated silica colloids a preliminary study
Animal reproduction, 2008Co-Authors: J M Morrell, A M Dalin, Heriberto RodriguezmartinezAbstract:Difficulties to be overcome in the widespread use of artificial insemination (AI) in mares are low sperm survival and poor sperm quality, which are encountered frequently among breeding stallions. Therefore, a method is needed to prolong the useable life of stallion spermatozoa destined for AI. In a preliminary study using 8 ejaculates from one stallion, density gradient Centrifugation or Centrifugation through a single layer of silica colloid appeared to prolong sperm motility compared to uncentrifuged spermatozoa, thereby potentially extending the useable life of treated stallion spermatozoa for AI. Furthermore, there was an improvement in sperm morphology, with the number of morphologically normal spermatozoa increasing from 42 to 60.5% and with the removal of approximately 60% spermatozoa with head or tail defects from the original population. No difference between the two Centrifugation methods, in terms of yield or duration of spontaneous motility, could be detected in this study. Either of these methods of colloidal Centrifugation could be a useful aid to preparing stallion spermatozoa for artificial breeding techniques, including AI.
Ülkü Anik - One of the best experts on this subject based on the ideXlab platform.
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Centri-voltammetry and biocentri-voltammetry: a review
Microchimica Acta, 2013Co-Authors: Ülkü AnikAbstract:Centri-voltammetry and biocentri-voltammetry are techniques that combine Centrifugation with voltammetry. This review covers (a) definitions; (b) experimental (cell) configurations; (c) effects of Centrifugation parameters; and (d) applications of the method to the determination of heavy metals and biological molecules. Specific examples include applications to the determination of xanthine, acetylcholine esterase activity, and of acetyl choline. Figure Centri-voltammetry can be defined as combination of Centrifugation with voltammetry. Combination of centri-voltammetry with biosensing systems is called biocentri-voltammetry.
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Centri-voltammetry and biocentri-voltammetry: a review
Mikrochimica Acta, 2013Co-Authors: Ülkü AnikAbstract:Centri-voltammetry and biocentri-voltammetry are techniques that combine Centrifugation with voltammetry. This review covers (a) definitions; (b) experimental (cell) configurations; (c) effects of Centrifugation parameters; and (d) applications of the method to the determination of heavy metals and biological molecules. Specific examples include applications to the determination of xanthine, acetylcholine esterase activity, and of acetyl choline.
Scott D. Emr - One of the best experts on this subject based on the ideXlab platform.
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Overview of Subcellular Fractionation Procedures for the Yeast Saccharomyces cerevisiae
Current Protocols in Cell Biology, 2004Co-Authors: Stephanie E. Rieder, Scott D. EmrAbstract:This unit provides an overview of Centrifugation-based fractionation procedures adapted for the yeast Saccharomyces cerevisiae. The goals, merits, limitations, and critical parameters of are discussed in order to facilitate the development of subcellular fractionation strategies. Topics include yeast cell lysate preparation, differential velocity Centrifugation, density gradient Centrifugation, and the analysis of subcellular fractions.