Method for measuring physical property values of a cell

A method of measuring physical property values of a cell having an isotropic or nonisotropic shape, the method comprising:

• applying an electric field to said cell at a frequency range within 10 kHz and 110 MHz;
• measuring an electric permittivity response from said cell based on the frequency range of the applied electric field, the measured electric permittivity response having a real part ∈′ and an imaginary part ∈″;
• determining a dielectric spectrum having a real part ∈′ and an imaginary part ∈″ about the cell based on the measured electric permittivity response and the isotropic or nonisotropic shape of the cell, wherein the dielectric spectrum is calculated by, at least in part, setting an arbitrary membrane capacitance Cm and an arbitrary cell cytoplasm electric conductivity κi, and carrying out a numerical analysis according to the shape of the cell by independently changing the membrane capacitance Cm and the cell cytoplasm electric conductivity κi and matching the real part ∈″ and the imaginary part ∈″ of the dielectric spectrum to the real part ∈′ and the imaginary part ∈″ of the measured electric permittivity response;
• determining a change Δ∈ in relative electric permittivity and relaxation time τ of said cell depending on the membrane capacitance Cm and the cell cytoplasm electric conductivity κi by fitting the real part ∈″ of the dielectric spectrum determined from the real part ∈′ of the measured electric permittivity response to a dielectric relaxation expression comprising a Cole-Cole type relaxation expression, provided as follows:
• ∈*(ω)=Δ∈/{1+(i×ω×τ)β}+∈˜+κi/(i×ω×∈0)
• including a Cole-Cole parameter β, an angular frequency ω, an electric permittivity of a vacuum ∈0, an electric conductivity in a low frequency limit κ1 and a relative electric permittivity in a high frequency limit ∈˜;
• forming a plurality of regression-expressions, provided as follows:
• Δ∈/P=f(Cm,κi)=(a×Cm)/(1+b×κi)
• τ=g(Cm,κi)=Cm×(C/κi+d)
• including constants a, b, c, d and a volume fraction of said cell P obtained from a model of the isotropic or nonisotropic shape of the cell, wherein the plurality of regression expressions correspond to the shape and dimensions of said cell based on the change Δ∈ in relative electric permittivity and the relaxation time τ;
• performing a multiple regression analysis according to the plurality of regression expressions and determining the constants a, b, c and d;
• and
• determining an experimental membrane capacitance Cm, exp and an experimental cell cytoplasm electric conductivity κi, exp of said cell by comparing the measured electric permittivity response and the plurality of regression expressions with each other.