scholarly journals Sperm Na+, K+-ATPase and Ca2+-ATPase activity: A preliminary study of comparison of swim up and density gradient centrifugation methods for sperm preparation

2018 ◽  
Author(s):  
Silvia W. Lestari ◽  
Manggiasih D. Larasati ◽  
Asmarinah ◽  
Indra G. Mansur
Keyword(s):  
Atpase Activity ◽  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Sperm Preparation ◽  
Preliminary Study

scholarly journals Sperm Selection and Embryo Development: A Comparison of the Density Gradient Centrifugation and Microfluidic Chip Sperm Preparation Methods in Patients with Astheno-Teratozoospermia

Life ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 933
Author(s):  
Cagla Guler ◽  
Sureyya Melil ◽  
Umit Ozekici ◽  
Yaprak Donmez Cakil ◽  
Belgin Selam ◽  
...  
Keyword(s):  
Density Gradient ◽  
Embryo Development ◽  
Microfluidic Chip ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Sperm Concentration ◽  
Gradient Methods ◽  
Semen Parameters ◽  
Preparation Methods ◽  
Sperm Preparation

In recent years, microfluidic chip-based sperm sorting has emerged as an alternative tool to centrifugation-based conventional techniques for in vitro fertilization. This prospective study aims to compare the effects of density gradient centrifugation and microfluidic chip sperm preparation methods on embryo development in patient populations with astheno-teratozoospermia. In the study, the semen samples of the patients were divided into two groups for preparation with either the microfluidic or density gradient methods. Selected spermatozoa were then used to fertilize mature sibling oocytes and the semen parameters and embryo development on days 3 and 5 were assessed. While the density gradient group was associated with a higher sperm concentration, motility (progressive and total) was significantly higher in the microfluidic chip group. No significant differences were observed in the fertilization rates or grade 1 (G1) and grade 2 (G2) proportions of the third-day embryos. Furthermore, while the proportions of the poor, fair and good blastocysts on day 5 did not differ significantly, excellent blastocysts (indicating high-quality embryos) were observed in a significantly higher proportion of the microfluidic chip group. When compared to the classical density gradient method, the microfluidic chip sperm preparation yielded sperm with higher motility and higher quality blastocysts at day 5; in patients with astheno-teratozoospermia.

scholarly journals Separation of Adenosine Triphosphatase of HK and LK Sheep Red Cell Membranes by Density Gradient Centrifugation

1965 ◽  
Vol 48 (6) ◽  
pp. 1125-1143 ◽  
Author(s):  
D. C. Tosteson ◽  
P. Cook ◽  
R. Blount
Keyword(s):  
Specific Gravity ◽  
Atpase Activity ◽  
Density Gradient ◽  
Adenosine Triphosphatase ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Red Cell ◽  
High Potassium ◽  
Red Cell Membrane ◽  
Red Cell Membranes

Membrane fragments from high potassium (HK) and low potassium (LK) sheep red cells were separated by density gradient centrifugation. Three preparations were studied: (1) HK membranes sonicated for 20 minutes, (2) HK membranes sonicated for 3 minutes, and (3) LK membranes sonicated for 3 minutes. The adenosine triphosphatase (ATPase) activity in the maximally disrupted preparation (1) was not sensitive to Na + K and was recovered in relatively small but heavy (specific gravity 1.19) fragments which made up no more than 8 per cent of the total membrane. Both Na + K-sensitive (S) and Na + K-insensitive (I) ATPase activity were found in the more gently broken up preparations (2) and (3) but the ratio of S- to I-ATPase was much greater in HK than in LK membrane fragments. S-ATPase activity in preparation (2) was about 50 per cent that observed in HK membranes prior to sonication. S-ATPase activity was recovered from the density gradient in relatively large but light (specific gravity 1.10) fragments. As was the case with the maximally disrupted preparation (1), I-ATPase activity in both preparations (2) and (3) was recovered in small but heavy (specific gravity > 1.20) fragments. The possibility that sensitivity of sheep red cell membrane ATPase to Na + K depends on the association between units containing the enzyme(s) and large, light, phospholipid-containing components is discussed.

scholarly journals Is pre-freeze sperm preparation more advantageous than post-freeze?

2021 ◽  
Vol 2 (1) ◽  
pp. 17-25
Author(s):  
Dimitra Apostolia Androni ◽  
Sophie Dodds ◽  
Mathew Tomlinson ◽  
Walid E Maalouf
Keyword(s):  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Optimal Timing ◽  
Success Rates ◽  
Clinical Practices ◽  
Sperm Preparation ◽  
Sperm Counts ◽  
Selection Step ◽  
Preparation Techniques

Human sperm cryopreservation is characterised to this day by sub-optimal success rates. Interestingly, a traditional approach to improving post-thaw outcome has been to integrate standard sperm preparation techniques into freezing protocols as a means of selecting sperm with the highest fertilisation potential prior to insemination. However, no consensus has been reached yet regarding the optimal timing (before or after freezing) of this selection step. Following analysis of a total of 20 human semen samples, which were divided into two aliquots prepared by density gradient centrifugation either before or after freezing, this study demonstrated higher post-thaw total (P < 0.0001), progressively motile (P = 0.005) and vital (P < 0.0001) sperm counts for frozen-prepared semen samples. The present study suggests that direct insemination with frozen-prepared sperm with minimal intervening post-thaw processing might be a more advantageous approach to current clinical practices, particularly for donor and patient intrauterine insemination programmes. Further research into cryopreservation-induced coiled sperm tail morphology is also warranted. Lay summary Freezing and storing of sperm in liquid nitrogen (’sperm cryopreservation') is the current method of choice for preserving the fertility of a wide scope of men. Nevertheless, sub-optimal sperm survival is still associated with traditional cryopreservation methods, namely 'slow freezing', and may affect fertility treatment success rates. Interestingly, a widely applied approach for selecting high-quality sperm before treatment has been to incorporate 'sperm preparation' techniques, such as density gradient centrifugation, in slow freezing protocols. There is, however, an ongoing debate regarding which is the optimal timing of this selection step: before or after freezing. In this study, we collected 20 human semen samples which were divided into two portions and subjected to density gradient centrifugation either before or after freezing. Post-thaw semen analyses demonstrated significantly improved sperm counts (P < 0.05) when density gradient centrifugation was performed before freezing, thus suggesting this approach to be more advantageous for current clinical practices.

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