A method for characterizing a biological tissue in vitro containing the following steps: a) Measurement of the electrical impedance of the biological tissue as a function of frequency, wherein an impedance spectrum Z(ω) is obtained; b) Matching of n model spectra Z m (ω) n to the measured impedance spectrum Z(ω), wherein each Z m (ω) n is determined by a formula which is selected from the family of formulae: Z m ω n = R S + Z CPE ω + Sum of Z Cell ω i for i = 1 to n, wherein for each i Z Cell (ω) i is the impedance of an electrically active layer i in the tissue which corresponds to a parallel circuit of the ohmic component R Cell i of this layer and the real capacitive component C Cell (ω)(N i) i of this layer according to Formula: ZCell ω i = R Cell i | | C Cell ω Ni i and wherein N i is the ideality of this real capacitive component C Cell (ω)(Ni) i and is always less than 1; wherein, for each n, the model spectra Zm(ω) n are in each case approximated to the impedance spectrum Z(ω) measured in Step a) by variation of at least one of the impedance-determining components R Cell i and capacitive component C Cell (ω)(Ni) i of each electrically active layer i in each case. c) Determination for each model spectrum Z m (ω) n the model spectrum which for each n is optimally matched to the measured impedance spectrum Z(ω), wherein the optimally matched model in each case is characterized in that it has the smallest residues compared with the measured impedance spectrum in each case; and d) Calculation of at least one variable selected from ohmic component R Cell and real capacitive component of each optimally matched model spectrum as the variable which characterizes the biological tissue. a) Measurement of the electrical impedance of the biological tissue as a function of frequency, wherein an impedance spectrum Z(ω) is obtained; b) Matching of n model spectra Z m (ω) n to the measured impedance spectrum Z(ω), wherein each Z m (ω) n is determined by a formula which is selected from the family of formulae: Z m ω n = R S + Z CPE ω + Sum of Z Cell ω i for i = 1 to n, wherein for each i Z Cell (ω) i is the impedance of an electrically active layer i in the tissue which corresponds to a parallel circuit of the ohmic component R Cell i of this layer and the real capacitive component C Cell (ω)(N i) i of this layer according to Formula: ZCell ω i = R Cell i | | C Cell ω Ni i and wherein N i is the ideality of this real capacitive component C Cell (ω)(Ni) i and is always less than 1; wherein, for each n, the model spectra Zm(ω) n are in each case approximated to the impedance spectrum Z(ω) measured in Step a) by variation of at least one of the impedance-determining components R Cell i and capacitive component C Cell (ω)(Ni) i of each electrically active layer i in each case. c) Determination for each model spectrum Z m (ω) n the model spectrum which for each n is optimally matched to the measured impedance spectrum Z(ω), wherein the optimally matched model in each case is characterized in that it has the smallest residues compared with the measured impedance spectrum in each case; and d) Calculation of at least one variable selected from ohmic component R Cell and real capacitive component of each optimally matched model spectrum as the variable which characterizes the biological tissue.