Specific steps:
1. Prepare a clean white paper;
2. Take the first cotton swab (do not touch the part of the absorbent cotton), extend it into the cavity, scrape back and forth 20 times against the inside of the left cheek (rotate the cotton swab from time to time), and need to fully contact the oral mucosa. Remove the cotton swab and let it dry naturally on white paper for 2-3 hours;
3. Take the second cotton swab, wipe it back and forth 20 times on the inside of the right oral cavity, put it on the same white paper, and dry it naturally for 2-3 hours;
4. Wipe the third cotton swab on the left and right sides 15 times, put it on the same white paper, and let it dry naturally. Collect six pieces repeatedly;
5. Make a mark, wrap it with white paper, and put it in an envelope;
6. Repeat the above steps to extract another person's oral mucosal epithelial cells, wrap them with white paper, mark them clearly, and put them in another envelope. Note: Please don't confuse the two cotton swabs! Please send it by express mail as soon as possible. In addition, do not use plastic bags, only paper materials.
