A portable and affordable aligner for the assembly of microfluidic devices

The incorporation of sophisticated capabilities within microfluidic devices often requires the assembly of different layers in a correct arrangement. For example, when it is desired to include electrodes inside microfluidic channels or to create 3D microfluidic structures. However, the alignment between different substrates at the microscale requires expensive equipment not available for all research groups. In this work, we present an affordable, compact and portable aligner for assembling multilayered composite microfluidic chips. The instrument is composed of aluminum machined pieces combined with precision stages and includes a digital microscope with a LED illumination system for monitoring the alignment process. An interchangeable holder was created for substrate fixing, allowing the bonding of PDMS with other materials. Microscopic visualization is achieved through any device with internet access, avoiding the need of a computer attached to the aligner. To test the performance of the aligner, the center of an indium tin oxide microelectrode on a glass substrate was aligned with the center of a microchannel in a PDMS chip. The accuracy and precision of the instrument are suited for many microfluidic applications. The small and inexpensive design of the aligner makes it a cost-effective option for small groups working in microfluidics.

Plasma IGF1 and 17β-Estradiol Concentrations During the Follicular Wave in Llamas

The aim of this study was to characterize the temporal association between follicular waves and circulating concentrations of 17β-estradiol (E2) and IGF1 in llamas. Follicular waves could be clearly divided in three phases: growth, plateau and regression; with a mean duration of 18.8 ± 0.32 days. All follicular waves showed overlapping, so that as one dominant follicle was regressing, another one was growing. E2 plasma concentration showed a wavelike pattern, similar to that followed by the dominant follicle; reaching its maximum concentration at the end of the growth phase and decreasing at the end of the plateau phase. IGF1 also showed variations during the follicular wave. It tended to increase during the growth phase and decreased toward Days 14 and 16. IGF1 reached its maximum concentration before E2 did (5 ± 0.8 vs. 7.2 ± 0.5 days after wave emergence) and before the maximum follicular diameter was attained (10.2 ± 0.46 days after wave emergence). Both hormones started to rise again in coincidence with the development of a new follicular wave. The observed profiles allow to suggest that IGF1 could have a role on folliculogenesis and ovarian steroideogenesis in llamas, as reported for other species.

309 MORPHOMETRICAL ANALYSIS OF THE LAMA GLAMA SPERM HEAD

During the last decades, the interest in breeding South American Camelids has increased, not only as companion animals but also for their high- quality fiber. Although several studies have been carried out on artificial insemination in Lama glama, this technique has not been widely applied in reproductive programs, principally due to the difficulty in collecting raw semen from males and the lack of knowledge about freezing/thawing techniques and semen characteristics. The aim of the present study was to objectively characterize llama sperm morphometry by a computer-assisted system, thereby increasing the knowledge on male llama physiology, leading to further developement of reproductive biotechnologies such as artificial insemination. Five semen samples were obtained by electroejaculation from each of 8 males, 6- to 10-year-old llamas of proven fertility. Smears were prepared from each sample and stained with Tinción 15® (Biopur S.R.L., Rosario, Argentina) and observed at x 1000 magnification. Images of sperm heads were captured by a Leica DC180 camera (Leica Microsystems Co., Wetzlar, Germany), obtaining 200 images from each sample. Binary images were obtained and area, length, width, equivalent circle diameter, curve length, curve width, perimeter, convex perimeter, roundness, and elongation were measured using QWin Plus (Leica Microsystems Co.). A total of 8005 sperm heads were measured. Descriptive statistics of the complete population was performed, with the following results obtained (mean ± SD): area (μm2) 20.09 ± 0.6, length (μm) 6.6 ± 0.3, width (μm) 4.14 ± 0.1, equivalent diameter ((μm) 5.06 ± 0.1, curve length (μm) 5.8 ± 0.3, curve width (μm) 3.48 ± 0.3, perimeter (μm) 18.54 ± 0.1, convex perimeter (μm) 17.34 ± 0.3, roundness 1.28 ± 0.04, and elongation 1.6 ± 0.01. Coefficients of variation were between 0.47 and 8.72%. A design considering the male as a fixed factor and the ejaculate as a nested factor was used for the purpose of identifying differences in morphometry between ejaculates of the same male and/or between males. Normality was tested using the Kolmogorov test. Significant differences between ejaculates of some males were found for curve length, curve width, perimeter, roundness, and elongation (P < 0.05). There were no intra-male differences for sperm head area, length, width, equivalent circle diameter, and convex perimeter. Of the parameters, there were significant differences between males for sperm area, length, equivalent circle diameter, and convex perimeter (P < 0.05). The differences found in sperm morphometry confirm the great polymorphism observed when subjectively evaluating llama semen morphology and make the establishment of a single pattern of normal llama sperm morphometry impossible.

Collection method, season and individual variation on seminal characteristics in the llama (Lama glama)

The objective of the present study was to evaluate the effect of semen collection method (electroejaculation "EE" as compared with the artificial vagina "AV"), the season (summer versus winter) and the male used on macroscopic and microscopic characteristics of ejaculates in llamas. A total of 110 ejaculates were collected from six males and 92 of them were analyzed. Ejaculate volume, concentration, total sperm and the following sperm characteristics were studied: motility, membrane function (HOS test), membrane integrity (CFDA/PI fluorochromes) and morphology. A mixed linear model, that considered season and collection method as the fixed variables and the male as the random variable, was used for the statistical analysis. Variability was found between males (p<or=0.05) when comparing the seminal characteristics. When considering the number of collections performed and the number of ejaculates discarded with each method, significant differences (p<0.01) were found between collection methods (EE and AV), with EE having a greater proportion of successful semen collections. There were significant differences (p<or=0.05) between collection methods for volume, sperm motility and membrane function. Ejaculates obtained by EE have a greater volume, sperm motility, live spermatozoa and sperm with functional membranes. Comparison of semen variables between the two seasons indicated that sperm concentration and sperm abnormalities were different (p<0.01). Ejaculates obtained during winter have greater sperm concentration and less sperm tail abnormalities than in summer. We conclude that semen variables have individual variation in llamas and are affected both by method of collection and season. The most desirable semen quality was obtained during winter using EE as the semen collection method.