Chapter 18 - Oocyte and zona imaging

Summary

Polscope imaging provides valuable information on the structure and architecture of themeiotic spindle and the zona pellucida (ZP), which helps predict fertilization, embryo development, and pregnancy. Differential interference contrast (DIC) is most efficient when imaging through glass coverslips, an impractical requirement for clinical in vitro fertilization (IVF), so most IVF laboratories employ variations of the DIC method, such as Hoffman modulation (HM). When imaging the oocyte for IVF, it is important to maintain tight temperature control, because both reduced and elevated temperature disrupts the integrity of the meiotic spindle. Spindles can be imaged non-invasively by polarized light microscopy. A quantitative polarized light microscope, the polscope, which uses circularly rather than plane polarized light, provides orientation-independent and, therefore, quantitative measurement of retardance in living specimens. Further studies are needed to determine whether spindle abnormalities predict aneuploidy as revealed by the more invasive preimplantation genetic screening (PGS).