Tlc plate

The determination of polyamines uses TLC [28 (link)]. For all samples, the cells were washed twice, then the cells were scraped off and centrifuged. The pellet was washed with PBS, and the supernatant removed. A total of 200 μL 2% perchloric acid was added to each cell pellet sample. After these samples were incubated overnight at 4 °C, 200 μL 5 mg/mL dansyl chloride (Sigma-Aldrich, Shanghai, China) acetone and 100 μL saturated sodium bicarbonate were added to each 200 μL supernatant or standard sample (spermine, spermidine, and putrescine) to dansylate the polyamines and neutralize the acid. After incubating these samples overnight in the dark at room temperature, 100 μL of 150 mg/mL proline (Sigma-Aldrich) was added to remove excess dansyl chloride. A total of 500 μL of toluene was used to extract the dansylated polyamine. The hair cell polyamine sample was added to the TLC plate (Dingguo, Beijing, China) at small points, and the solution was chromatographed with a 2:3 cyclohexane–ethyl acetate developing solution for 1.5 h. After the TCL plate was dried, it was visually observed by ultraviolet rays with a wavelength of 365 nm, and the TCL plate image was photographed and stored.