Search

Abstract: We present a simple optical micro-system used to measure the transmission spectra of oocytes in order to qualify their maturation stage. Two applications of the device are possible: (i) the evaluation of the maturation stages of oocytes, and (ii) the development of a fertilization indicator. For the first application, GV, MI and MII oocytes were also analysed. Transmission spectra allow the 3 maturation stages to be identified but cannot be used to estimate the maturity of an unknown oocyte. Oocytes are subject to continuous development. This is why spectral separation of the 3 maturation stages cannot be made although they can be visually identified. However, the visual observation remains biologist-dependent. We therefore investigated the temporal maturation evolution of the oocytes in terms of transmission spectra and probability analysis. Results show that oocytes to be fertilized should not only be chosen in the MII stage, but also at the right time during the MII stage. This particular aspect requires further investigation. However, spectral measurements could be used as a technique for monitoring the maturation evolution of the oocytes. Fertilized oocytes exhibiting fertilization abnormalities were also tested. The device proved to be an efficient fertilization indicator. [Copyright &y& Elsevier]

Abstract: In vitro Fertilisation (IVF) is one of the therapeutic techniques offered to patients suffering from reproduction difficulties. Among the various steps involved in gamete manipulation, especially in intra cytoplasmic sperm injection (ICSI), the determination of the cell to be fertilised is critical. Usually, the choice of the oocyte relies on a visual checking of the maturity of the cell and on its morphological properties. Our current work deals with the fabrication of labs-on-chip (LOC), devoted to the characterisation of the cells before fertilisation. They consist of a platform that includes different analysis tools and a system that allows the accurate displacement between the different analysis bays. The first issue that must be addressed is the capture, the transportation and the trapping of a single oocyte on the LOC surface. We recently proposed a system based on micro-translators used for long distance transportation and micro-fluidics for accurate trapping. In this paper, we demonstrate a full micro-fluidic system which allows both, the long range displacement and the accurate trapping of a single oocyte. This simplifies the LOC because there is no more need for any micro-motor or complex mechanical systems. We also demonstrate the first optical sensor that quantifies the degree of maturity of the cell to be fertilised. This sensor can also be used as a fertilisation indicator. [Copyright &y& Elsevier]