Determination of the number of cells in preimplantation embryos by using noninvasive optical quadrature microscopy in conjunction with differential interference contrast microscopy.
The number of cells in a preimplantation embryo is directly correlated to the health and viability of the embryo. There are currently no methods to count the number of cells in late-stage preimplantation embryos noninvasively. We assessed the ability of optical quadrature microscopy (OQM) to count the number of cells in mouse preimplantation embryos noninvasively. First, to test for possible light toxicity, we exposed two-cell mouse embryos to OQM and differential interference contrast (DIC) microscopy and assessed their ability to develop to the blastocyst stage. We found no inhibition of development from either mode of microscopy for up to 2 h of light exposure. We also imaged eight-cell to morula stage mouse preimplantation embryos by OQM nd developed two methods for counting the number of cells. The contour signature method (CSM) used OQM images alone and the phase subtraction method (PSM) used both OQM and DIC images. We compared both methods to standard cell counting techniques and found that the PSM was superior to all other noninvasive cell counting methods. Our work on mouse embryos should be applicable to human embryos. The ability to correctly count the number of cells in human preimplantation embryos could lead to the transfer of fewer embryos in in vitro fertilization (IVF) clinics and consequently a lower rate of high-risk multiple-infant births.
Newmark
Judith A
JA
Department of Biology, Center for Subsurface Sensing and Imaging Systems (CenSSIS), Northeastern University, Boston, MA 02115, USA.
Warger
William C
WC
Chang
ChihChing
C
Herrera
Gustavo E
GE
Brooks
Dana H
DH
DiMarzio
Charles A
CA
Warner
Carol M
CM
D000818:Animals; D001755:Blastocyst / Q000166:cytology*; D002452:Cell Count / Q000379:methods; D047108:Embryonic Development / Q000502:physiology; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008857:Microscopy, Interference / Q000379:methods*; D055095:Optics and Photonics; D011247:Pregnancy