Major liquid-liquid microextraction methods include nanomanipulation, nano-DESI, and the Single-probe MS. In nanomanipulation coupled nanospray MS, introduced by Phelps et al. , a quartz probe punctures the cell membrane, and a nanoESI emitter is used to extract analytes. Nano-DESI, developed by the Laskin group in 2012 , utilizes a primary capillary to deliver solvent to the sample and a secondary capillary for solution extraction and ionization. Originally designed for MS imaging, nano-DESI was later adapted by Lanekoff et al. for single-cell analysis . In the subsequent sections of this review, we will provide a detailed discussion on the applications of the Single-probe techniques in singlecell analysis.