Aberrations and the Benefit of Their Correction in Confocal Microscopy - Adaptive Optics for Biological Imaging - page 67

he goal of this study was to the quantify the specimen-induced aberrations for a representative variety
of biological specimens. herefore, we had to select a set of common biomedical specimens. Some of them
are listed in Table 4.2 and the specimen numbers listed there will be referenced in the following discussion.

4.11 Example Results for High Numerical Aperture

Ater the described Zernike mode extraction, each coeicient M i may be represented as a Zernike mode
pseudo-image that shows the variation of M i as one scans across the specimen. Figure 4.15 displays an
example for the C. elegans specimen. Here modes 5 through 12 are depicted. he total Zernike igure is
calculated using

(

) /

1 2

22

M i

2

.

i = 5

For the purpose of designing and implementing adaptive optics, it is important to consider the
variations of the aberrations across the ield of view. he mean and the standard deviation for each
mode were calculated from maps such as shown in Figure 4.15; a result for the C. elegans is shown in

Table 4.2 Approximate hickness, Lateral Scan Range, and Embedding Medium of the
Specimens We Investigated
Specimen Number

Description Embedding hickness (μm) Lateral Scan (μm)

1 Brain tissue, rat PBS 30 120 × 120

2 Mouse oocyte PBS 80 125 × 125

3 Liver tissue, mouse PBS 20 20 × 20

4 Striated muscle, rat PBS 40 50 × 50

5 C. elegans Agar gel 40 50 × 50

6 Vas deferens, rat PBS 30 50 × 50

PBS, Phosphate-bufered saline.

Total Zernike Mode 2—Tip Mode 3—Tilt

2 3

2

1

1 0

‒ 1

‒ 2

0 ‒ 3

2 Mode 4—Defocus Mode 5—Astigmatism Mode 6—Astigmatism Mode 7—Coma

1

0

‒ 1

‒ 2

Mode 8—Coma Mode 9 Mode 10 Mode11—Spherical (1st) Mode 12

Figure 4.15 Zernike mode pseudo-images of the specimen number 5, C. elegans . he Zernike mode amplitudes
M i of modes 2 through 12 (for the Zernike mode units, see deinition in Equation 4.4) are depicted.