## 4 Discussion  
Our goal was to obtain a higher initial number of cells with homogenized characteristics using the explant method. For this purpose, we extracted cells from the two UC tissues that contain the most MSCs: Wharton's jelly and subamnion. To increase the amount of isolated cells, we removed the tissue fragments on day 10 and transferred them to new dishes. A comparison between the method that we used and other explant methods is given in Table 2.  
Figure 8: Quantitative PCR results for expression of OCT4A, OCT4B, OCT4B1, NANOG, and SOX2 in WJ-MSCs and SA-MSCs at passage 3. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Author** & **Origin of the** **Explan** & **Size of the Explants** & **Discarding of the Explants (Day)** & **Initial Cell Number** & **Time for Reaching** & **Population Doubling Time (on** **Coales/com**)** & **Averg/Passage Number** \\ \hline Our results & WJ & 10 mm\({}^{2}\) & 10 with transferring & \(5-6\times 10^{4}\) cells/cm\({}^{2}\) or & -29.2 (73) & -18 \(\times 10^{4}\) cells/cm\({}^{2}\) & -29.2 (73) \\  & SA & 10 mm\({}^{2}\) & to new culture dish for & \(3-4\times 10^{4}\) cells/cm\({}^{2}\) or & -31.9 (73) \\  & 10 mm of UC & another 10 days & \(6.7\times 10^{4}\) cells/cm\({}^{2}\) & 21 & \\  & & 5 mm of UC & 10 & \(3.7\times 10^{4}\) cells/cm\({}^{2}\) & -10 & ND \\  & & 1 mm of UC & \(2.6\times 10^{4}\) cells/cm\({}^{2}\) & 8-10 & -10 \\  & & \({}^{-1}\) cm\({}^{2}\) & 10 & \(2.15\times 10^{4}\) cells/cm\({}^{2}\) & 10-12 & -26.6 h (71) \\  & UC & 1-3 mm\({}^{2}\) & ND & ND & 22 & -23 h (76) \\  & WJ & 1-3 mm\({}^{2}\) & 10-12 & ND & -24 h (76) \\  & Ammon & 2-3 mm\({}^{2}\) & 10-12 & ND & 21 & ND \\  & & & & ND & ND \\  & Ammon & \({}^{-1}\) inch dye/2.5/cm\({}^{2}\) & ND & ND & ND \\  & Ammon & 2-3 mm\({}^{2}\) & -3 mm\({}^{2}\) & -35.25 h up to P12 & -32.5 h up to P12 \\ [PERSON] et al., 2021 [44] & WJ & 2-3 mm\({}^{2}\) & 14 & ND & 14 & -32.4 \(\pm\) 3.6 h up to P12 \\  & Perivascular region & 2-3 mm\({}^{2}\) & & & 14-21 & -28.8 \(\pm\) 4.9 h up to P12 \\  & [PERSON] et al., 2014 [45] & WJ & 1-2 mm\({}^{2}\) & 4-21 & NA & 14-21 & ND \\  & [PERSON] et al., 2015 [46] & WJ & 1-2 mm\({}^{2}\) & 9-12 & NA & 201.1 \(\pm\) 4.4 & ND \\  & [PERSON] et al., 2017 [47] & UC & 5 cm\({}^{2}\) & 14 & ND & ND & 38.9 h (79) \\  & [PERSON] et al., 2018 [48] & WJ & 10-12 & ND & 18-22 & -49.3 h (71) \\  & [PERSON] et al., 2010 [69] & WJ & 2-4 mm & ND & NA & 12 & -28.5 h up to P3 \\  & & 10 mm & & & & -33.4 \(\pm\) 1.2 h up to P3 \\  & & 10 mm & & & & -33.4 \(\pm\) 1.2 h up to P3 \\  & & & & & & \\ \hline [PERSON] et al., 2022 [73] & WJ & -1.2 mm & 8 & NA & 8 & ND \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Comparison of the method that we applied to similar explant methods used for isolation of MSCs from UC. In Table 2, we can see a comparison between the method that we used and other similar methods for isolation of MSCs from UC tissues. There is great variation between the size of the explants in the different studies and the number of explants per culture dish/well. As for the discarding of the explant from initial isolation site, the earliest mentioned period was 8 days (13), and our results were second best with 10 days. Another interesting parameter is the initial cell number per cm/cm\({}^{2}\) of WJ, where we obtained better results in comparison to the other papers which used the same way of expression of the cell number. As for the confluence and population doubling time, our results were comparable with those of the other authors, with very few accomplishing better times. There are however several points that needs to be taken in account. First of all, not all the authors provided all the necessary data, which would have allowed us to perform a full and detailed comparison of the used methods. This is well presented in Table 2, where we can clearly see that the authors often do not present data on the initial cells number, cell doubling time, etc.