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CHAPTER 5.1
al., 2007) showing a clear three dimensional movement of the flagella. The exact forces acting on
moving spermatozoa inside different types of chambers have, so far, not been studied. However, the
differences in motility outcomes between chambers of comparable depths indicate that spermatozoa
are influenced to a large extent. If a diluter with small particles is used for motility analysis, the
movement of (the tail of) the spermatozoa makes these particles move over a wider surface through
initiation of waves, rather than through direct contact with the tail only. These waves might interfere
more with motility in disposable chambers with fixed walls when compared to the menisci that
create the border in disposable chambers or the WHO slide. This phenomenon can be easily
visualized when looking at speedboats on rivers with natural banks rather than canals with concrete
banks. The latter will result in more reflection of the waves, as such disturbing the water surface to a
bigger extent when compared to smooth natural banks (Fig. 3). It is hypothesized the same principle
occurs in disposable chambers with fixed wall (total reflection as in Fig. 3A), and as such interfere
with motility, whereas in chambers with a loose cover slip the reflection might be minimized by the
menisci creating the border (as in Fig. 3B). In this aspect, disposable chambers might cause different
forces in the fluid filled chamber in comparison to the reusable chambers or the WHO prepared slide,
in which the fluid menisci bordering the surface might partially absorb these “waves”.
A.
B.
Fig. 3. Schematic presentation of a virtual speed boat (proxy for sperm cell) and the waves as they
are (A) completely reflected by concrete borders, and (B) only partially reflected by the
natural borders of a river absorbing a big part of the waves before reflection.
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