## 3 Results  
The outcomes, as shown in Figure 1 and Supplementary (Figures S1-S9)--images of Figure 1 in high resolution, demonstrate how the staining process affected the visualized quantities of CE. Silver proteinase (1% and 5%) staining had a layer of the stain on the \begin{table}
\begin{tabular}{l c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Stain**} & \multicolumn{2}{c}{**Exposure Time, Rature, \(\circ\)C**} & \multirow{2}{*}{**Filter**} & \multicolumn{2}{c}{**X-ray Voltage, Current, \(\mu\)A**} & \multicolumn{2}{c}{**Scans Averaged**} & \multicolumn{2}{c}{**Size (\mu\)m**} & \multicolumn{2}{c}{**Heim (\mu\)m**} & \multicolumn{2}{c}{**Beam**} & \multicolumn{2}{c}{**Minimum Correction**} & \multicolumn{2}{c}{**Maximum Error CS to Image Conversion**} \\  & \multicolumn{1}{c}{} & & & & & & & & & & \\ No stain (70\%) & - & - & Al 0.2 mm & 45 & 550 & 3 & 8.87 & 10 & 20 & 0.001 & 0.03 \\ Ethanol & & & & & & & & & & & \\ \hline Silver & & & & & & & & & & & \\ Protein, & 24; 48 & 25; 40 & no filter; & 40; 45 & 550; 600 & 3 & 8.87 & 10 & 0 & 0.006–0.01 & 0.02–0.03 \\
1\% (70\%) & & & & & & & & & & & \\ Ethanol & & & & & & & & & & \\ \hline Eosin, 1\% (70\%) & 24; 48 & 25; 40 & no filter & 40 & 600 & 3 & 8.87 & 10 & 0 & 0.01 & 0.03 \\ Ethanol & & & & & & & & & & & \\ \hline IZK1, 1\% (70\%) & 24; 48 & 25; 40 & Al 0.2 mm; & 45; 50 & 500; 550 & 3 & 8.87 & 10 & 30 & 0.002–0.005 & 0.017–0.025 \\ Ethanol & & & & & & & & & & & \\ \hline Silver & & & & & & & & & & \\ Protein, & 24; 48 & 25; 40 & no filter; & 40; 45 & 550; 600 & 3 & 8.87 & 10; 20 & 21 & 0.002–0.004 & 0.025–0.035 \\
5\% (70\%) & & & & & & & & & & \\ Ethanol & & & & & & & & & & \\ \hline Eosin, 5\% (70\%) & 24; 48 & 25; 40 & Al 0.2 mm & 45 & 550 & 3 & 8.87 & 10 & 21 & 0.002–0.003 & 0.025 \\ Ethanol & & & & & & & & & & \\ \hline IZK1, 3\% (70\%) & 24; 48 & 25; 40 & Al 0.5 mm; & 50; 65 & 380; 500 & 3 & 8.87 & 10 & 41 & 0.002–0.003 & 0.06–0.09 \\ Ethanol & & & & & & & & & & \\ \hline PMA, 1\% (70\%) & 24; 48 & 25; 40 & Al 0.5 mm; & 50; 65 & 380; 500 & 3 & 8.87 & 10 & 41 & 0.001–0.002 & 0.07–0.09 \\ Ethanol & & & & & & & & & & & \\ \hline PTA, 1\% (70\%) & 24; 48 & 25; 40 & Al 1 mm & 65 & 380 & 3 & 8.87 & 10 & 41 & 0.001 & 0.075–0.1 \\ ethanol & & & & & & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: MicroCT scan settings for contrast stain CE (HH25-HH27 embryonic stage), n = 10.  
external tissues of CE, which increased its natural size and distorted the outlines in addition to having weak differential contrast. Figure 1 also shows a low level of general and differential contrast at staining with 1% silver proteinase and eosin solutions. Perhaps these results originate from an inadequate amount of stain concentration. The key limiting element in this aspect, according to [PERSON] et al. [32], is the low concentration of eosin employed for soft tissue contrast. However, in our case, staining with eosin, particularly at 5% concentration, caused deformations in the embryo tissues as well as a significant overall reduction in the volume of the tissues, which, in the opinion of some [36], may cause artifacts that are mistaken for anomalies of embryonic development. The relative rise in general contrast level of CE when stained with 1% I2 KI and 5% silver proteinase and eosin solutions does not allow for obvious differentiations of organs and tissues. All of the techniques of coloring described above permitted the use of filters that only contained a high degree of transmitted radiation or scanning without a filter at all, which increased the number of picture defects and decreased image quality. Simultaneously, the exposure duration and temperature had little effect on the outcome. Staining with 3% I2 KI and 1% solutions of PMA and PTA (Figure 2) made it possible to achieve a high level of general contrast of CE at embryonic stage HH25 (5 day) and gave more histologically interpreted data. This is evidenced by both the use of 0.5-1 mm Al filters (Table 2) during scanning and the low histogram (grey value) profile of the area around the CE.