Theoretical value 3.3: after adjustment 2.3 ng
||Human Homo sapiens
||Park K, Jang J, Irimia D, Sturgis J, Lee J, Robinson JP, Toner M, Bashir R. 'Living cantilever arrays' for characterization of mass of single live cells in fluids. Lab Chip. 2008 Jul8(7):1034-41 p.1040 table 3PubMed ID18584076
||D. A. Wolff and H. Pertoft, Separation of HeLa cells by colloidal silica density gradient centrifugation. I. Separation and partial synchrony of mitotic cells. J. Cell Biol., 1972, 55, 579–585PubMed ID4571230
||P.1035 left column 3rd paragraph: "One of the direct methods for measuring cell mass is the use of micromechanical resonant cantilever mass sensors for measurement and characterization of single cells. The resonance frequency of a cantilever is inversely proportional to the square root of the mass. Therefore, the mass of the entities attached to the cantilever can be directly calculated from the resonance frequency of the cantilever." P.1040 right column 3rd paragraph: "The measured mass from the frequency response was compared with the estimated value calculated from the cell density and the cell volume. The volume of the cell was measured from the confocal microscope images by Image J (Wayne Rasband, National Institute of Health, USA), and the published value (primary ref) for the density of the cell was used."
||P.1040 right column bottom paragraph: "Table 3 shows the measured cell mass and the estimated cell mass for comparison. As shown in Table 3, the measured values and the estimated values are close to each other. One of the probable reasons for the difference was the limited growth of a cell on a cantilever, due to the cantilever's small surface area, where the cell was constrained to grow only on the cantilever. The cells on the cantilevers were actually smaller than typical HeLa cells. Normally, HeLa cells occupy about 1600 μm^2 on a flat surface [ref 34] but the cells in Fig. 7 are confined on the cantilever with an area of 400 μm^2." The cells in ref had volumes of 2349 µm^3 and 3857 µm^3. Value is mean mass of both cells. This gives ~3×10^8 cells/gram and 4.3×10^8 cells/gram for theoretical and post-adjustment values, respectively.