Comparison of the Effect of Microchip and Density Gradient Methods in Intrauterine Insemination Cycles

Abstract Studies on normal human reticulocytes have been limited by a lack of methods for effective reticulocyte enrichment. This study shows a convenient new approach for selective enrichment of reticulocytes from normal blood samples. We have developed a modified arabinogalactan density gradient that contains high potassium levels, approximating the internal cation composition of red blood cells (RBC). The low-density populations from this gradient are enriched in reticulocytes, and the highly selected lowest density fraction shows a much higher reticulocyte enrichment than that obtained with high sodium chloride arabinogalactan density gradients, or other previously reported density gradient methods. We found that this improved isolation is caused by suppression of potassium loss and reticulocyte dehydration via chloride (KCI) cotransport. When the low-density fraction of RBC from a high- potassium gradient was subsequently incubated in high sodium chloride medium and reseparated on a sodium chloride density gradient, the reticulocytes dehydrated and were recovered in high-density fractions. The highest-density fractions from this secondary gradient yield 95% to 99% reticulocytes. We anticipate that this method will benefit investigators who require reticulocyte enriched populations for a wide variety of applications.

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

Life ◽

10.3390/life11090933 ◽

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.

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