ASTM F2149-16

3.1 The electrical sensing zone method for cell counting is used in tissue culture, government research, and hospital, biomedical, and pharmaceutical laboratories for counting and sizing cells. The method may be applicable to a wide range of cells sizes and cell types, with appropriate validation 3.2 The electrical sensing zone methodology was introduced in the mid-1950s (9). Since this time, there have been substantial improvements which have enhanced the operator's ease of use. Among these are the elimination of the mercury manometer, reduced size, greater automation, and availability of comprehensive statistical computer programs.

3.3 This instrumentation offers a rapid result as contrasted to the manual counting of cells using the hemocytometer standard counting chamber. The counting chamber is known to have an error of 10 to 30 %, as well as being time-consuming 1.1 This test method, provided the limitations are understood, covers a procedure for both the enumeration and measurement of size distribution of most all cell types. The instrumentation allows for user-selectable cell size settings and is applicable to a wide range of cell types. The method works best for spherical cells, and may be less accurate if cells are not spherical, such as for discoid cells or budding yeast. The method is appropriate for suspension as well as adherent cell cultures 1.2 Cells commonly used in tissue-engineered medical products 1.3 Electrical sensing zone instrumentation (commonly referred to as a Coulter counter) is manufactured by a variety of companies and is based upon electrical impedance. This test method, for cell counting and sizing, is based on the detection and measurement of changes in electrical resistance produced by a cell, suspended in a conductive liquid, traversing through a small aperture (see Fig. 11.4 Limitations are discussed as follows: