All four categories of cells were analyzed using the Singleprobe SCMS method. 30 cells in each group were analyzed in both positive and negative ion modes, and 240 cells in total were measured. To minimize potential batch effects, glass coverslips containing cells from these four groups were placed on the XYZ-stage, and cells were randomly selected for measurements. *Cells were washed using AF solution (0.9%) prior to sequential processing. Washed cells were subjected to LN2 quenching (Groups 2 and 4) or no quenching (Groups 1 and 3), dried (freeze drying or at room temperature (RT)) in a vacuum (SpeedVac) and analyzed without storage or after storage at -80 °C (48 h).