CASA-Mot technology: how results are affected by the frame rate and counting chamber.

For over 30 years, CASA-Mot technology has been used for kinematic analysis of sperm motility in different mammalian species, but insufficient attention has been paid to the technical limitations of commercial computer-aided sperm analysis (CASA) systems. Counting chamber type and frame rate are two of the most important aspects to be taken into account. Counting chambers can be disposable or reusable, with different depths. In human semen analysis, reusable chambers with a depth of 10µm are the most frequently used, whereas for most farm animal species it is more common to use disposable chambers with a depth of 20µm . The frame rate was previously limited by the hardware, although changes in the number of images collected could lead to significant variations in some kinematic parameters, mainly in curvilinear velocity (VCL). A frame rate of 60 frames s-1 is widely considered to be the minimum necessary for satisfactory results. However, the frame rate is species specific and must be defined in each experimental condition. In conclusion, we show that the optimal combination of frame rate and counting chamber type and depth should be defined for each species and experimental condition in order to obtain reliable results.

Efecto de la cámara de recuento utilizada sobre los parámetros espermáticos, analizados con el ISASv1® / Effect of counting chamber on seminal parameters, analyzing with the ISASv1®

Introducción: El uso de las cámaras de recuento condiciona los valores de concentración y movilidad espermática debido a su tipo de carga (capilaridad o desplazamiento de la gota) y a la altura que presenten. Recientemente, se han introducido nuevas cámaras, tanto desechables (ISAS®D4C) como reusables (Spermtrack®) con diversas alturas en cada caso. Objetivo: El objetivo del presente trabajo es validar su uso, analizando diversos parámetros espermáticos con un sistema CASA, el ISASv1®. Material y método: Se analizaron muestras de donantes voluntarios (10 para las desechables y 5 para las reusables), analizando el efecto del tipo de cámara, de la altura, del tiempo de carga y del tiempo de análisis. Resultados: Los resultados obtenidos no mostraron diferencias significativas con el tiempo de carga para las cámaras reusables ni con el tiempo de análisis en ninguna de las cámaras. Discusión: La cámara reusable de 10 μm y las desechables de 10, 16 y 20 μm no mostraron diferencias entre sí, mientras que la reusable de 20 μm presentó resultados significativamente diferentes con respecto a las demás, por lo que su uso (siguiendo la recomendación de la Organización Mundial de la Salud) debe hacerse teniendo en cuenta este hecho. Conclusión: Las nuevas cámaras ofrecen un resultado muy homogéneo, con independencia del tiempo de carga o de análisis (AU)

Introduction: The use of counting chambers conditions the sperm concentration and motility values by their type of filling (capillary or drop displacement) and chamber height. We have recently introduced new chambers, both disposable (ISAS®D4C) and reusable (Spermtrack®), with different heights in each case. Objective: This study has aimed to validate its use by analyzing different sperm parameters with a CASA system, that is, the ISASv1®. Material and method: Samples from volunteer donors (10 for the disposable and 5 for reusable), analyzing the effect of chamber type, height, filling and analysis time, were used. Results: The results obtained showed no differences within the filling time for the reusable chambers, or the analysis time in any cases. Discussion: The 10 microns reusable chamber and disposable, 10, 16 and 20 microns showed no differences between them. However, the reusable 20 microns showed significantly different results, so its use (as recommended by WHO) should be taking this into account. Conclusion: The new chambers offer very consistent results, independent of filling or time of analysis (AU)