Figure 1.
Analysis of Raman spectrum from a mature oocyte.
Average Raman spectrum collected from the cytoplasm of a mature oocyte annotated to show the major peaks present in the wavenumber region 800–1760 cm−1, which can be attributed to specific proteins or lipids. Abbreviations str. and def. refer to vibrations arising from stretches and deformations, respectively.
Table 1.
Description of morphological features used to grade oocytes.
Figure 2.
Principal component analysis of data from immature (IMM) oocytes and oocytes matured in vitro (MIV).
(A): Biplot showing the scores of each datum obtained from IMM and MIV oocytes plotted against the first and second component axes generated during PCA. Separation of immature and mature oocytes is observed along both the first and second axis. (B): Loadings for the first two Principal Components generated for the immature and mature datasets.
Figure 3.
Box-plot showing predictive ability of logistic regression algorithm.
Validation group consisted of IMM (immature: n = 15), MIV (matured in vitro: n = 15), NO (naturally ovulated: n = 38) and SO (superovulated: n = 59) oocytes. Within each box-plot, the narrow line shows the median, while upper and lower lines indicate first and third quartiles, with black whiskers extending 1.5 times the inter-quartile range in both directions: data outwith of this range are considered outliers, annotated by crosses.
Figure 4.
Principal component analysis and canonical variate analysis of data from oocytes.
Scatter plot of oocytes that were naturally ovulated (NO), superovulated (SO) or matured in vitro (MIV), showing the scores of each datum against (A): the first and fourth component axes generated during PCA and (B): the first and second canonical variate axes generated during CVA.
Figure 5.
High 1605∶1447 cm −1 protein-to-lipid ratio is a good indicator of oocyte quality.
(A): Scatter plot showing the ratios of the intensity of the Raman peak located at 1605 and 1447 cm−1 for each mean spectrum derived from the SO (superovulated) oocyte group. Results are presented according to the grade of the oocyte, as judged by its morphological appearance. The dashed line indicates the cut-off (0.3752) as determined by analysis of the ROC curve. (B): Box-plot showing the ratios of the intensity at 1605 and 1447 cm−1 for Grade 1 (good quality; n = 24) and Grades 2–5 (poor quality; n = 35) superovulated (SO) oocytes, oocytes collected after natural ovulations (NO; n = 38) and those which had been matured in vitro (MIV; n = 15). Within each box-plot, the narrow line shows the median, while upper and lower lines indicate first and third quartiles, with black whiskers extending 1.5 times the inter-quartile range in both directions: data outwith of this range are considered outliers, annotated by crosses. The dashed line indicates the cut-off (0.3752) as determined by analysis of the ROC curve for the SO oocyte data presented in (A).