Concentration and integrity index of circulating free DNA in the general Mexican population of Jalisco, Mexico Introduction. The concentration and integrity of cell free DNA (cf- DNA) are diagnostic and prognostic biomarkers in multiple diseases. Objective. To determine the concentration and integrity index of cf- DNA in peripheral blood of individuals from Jalisco, Mexico. Method. Peripheral blood from 117 individuals was analyzed. cf- DNA was quantified by Qubit 2.0 fluorometry and by ALU115 q-PCR. Integrity index was determined by the ALU247/ALU115 ratio by q-PCR. Results. The mean concentration of cf-DNA was 294 ng/ml by fluorometry and 108.08 ng/ml by q-PCR. Integrity index, by the ALU247/ALU115 ratio was 0.45. The concentration of cf-DNA showed a significant difference by age group, but not by sex. The integrity index did not show significant differences by sex or age groups. Conclusions. There are wide differences in cf-DNA between the two procedures used here, as well as compared to other populations.