CRi CRi

Skip to content

Oosight™ FAQs

  • What are the benefits of imaging spindles?

    The benefits of imaging spindles include:

    • The presence of an intact spindle can be used to assess egg health.
    • The spindle is an accurate identifier of egg maturation. Polar body extrusion often falsely identifies eggs as mature well before they reach MII.
    • Significant spindle migration from the polar body (i.e., >90°) is indicative of compromised egg health.
    • Spindle morphology has been correlated with chromosomal abnormalities, such as aneuploidy, and can be both observed and measured using Oosight's retardance and orientation calculations.
    • ICSI with the spindle at 6 o'clock results in fewer fragmented embryos.
    • The spindle is a good indicator of sub-optimal extrinsic factors such as temperature and pH.

  • What are the benefits of imaging the tri-laminar zona pellucida?

    The benefits of imaging the tri-laminar zona pellucida include:

    • The retardance of the inner zona pellucida has shown a strong correlation to pregnancy, offering a useful metric to include in grading quality.
    • The alignment of glycoproteins of the inner zona can identify weak points or disrupted morphology.
    • The Oosight's pseudocolor map of retardancecan help identify weak points of molecular order in the zona, either for assisted hatching and/or biopsy.

  • Can I see the spindle while doing micromanipulation?

    Yes, you can see the spindle through your microscope's eyepieces and in the live Oosight Video window on the computer monitor. With the new HC mode, you can now see the spindle in Hoffman contrast!

  • What is birefringence?

    The spindle and zona pellucida both exhibit an intrinsic optical property called "birefringence". This is due to the oriented microtubule structure of the spindle and the oriented glycoproteins of the zona pellucida, respectively. Birefringence, also known as double refraction, is an optical phenomenon that occurs when a polarized beam passes through an anisotropic structure (e.g., the spindle) causing the beam of light to be split into two polarization components, where the velocity of one is slowed down relative to the other.

  • What is retardance?

    "Retardance" is the distance between the faster and slower beams leaving a birefringent material. Like any distance, it can be measured in miles, inches, kilometers, meters, millimeters, micrometers or nanometers (nm). We report it as nanometers on a per pixel basis in a megapixel image. Data have shown that higher mean spindle and inner zona retardances both correlate to egg health.

  • Why don't I see a spindle in all or the majority of eggs that I am imaging?

    Most of the time, the reason for not seeing the spindle is either that the eggs are not fully matured, you need to rotate the egg, or your temperature-controlled stage is not maintaining the egg at its optimal temperature. Glass-heated stages tend to yield the best thermal stability as compared to metal heated stages. Large open-aperture metal stages (i.e., =25mm) are not suitable as they create too much of a heat sink effect, and lead to spindle de-polymerization. A lack of a visible spindle may also indicate other environmental or biological issues.

  • Can I use the Oosight imaging system on any microscope?

    The system can be integrated to fit most research-grade Microscopes that have 100W illumination, including:

    • Leica:
      DMI-IRB, DMI-IRE, DMI-x000 series
    • Nikon:
      Diaphot, Diaphot TMD, Diaphot 200/300, TE-200/300, TE2000, Eclipse Ti
    • Olympus:
      IX-50/70/80, IX-51/71/81
    • Zeiss:
      Axiovert 100/135, Axiovert 200, AxioObserver series

  • Is the Oosight system compatible with my laser system?

    The Oosight system has been adapted for use on workstations outfitted with the Hamilton-Thorne Biosciences Zilos and XY-Clone laser systems, as well as the Research Instrument's Saturn and Saturn-Active system. Contact CRi for additional details.

  • Can I export data into my database?

    With the 'export to clipboard' function, meaningful spindle and zona data can be easily exported to most database programs.

  • Can the system print reports?

    The new "Reports" tool allows you to not only print images, but also any data and related notes associated with images for any given patient, sample and/or session. Reports are also automatically saved into PDF format for easy electronic handling.