Correlation of the DNA Concentration of Human Samples to Electrical Bioimpedance Measurements: A Pilot Study

It is necessary to evaluate the total deoxyribonucleic acid (DNA) concentration in gene expression assays. The existing techniques require equipment that is expensive for many labs in developing countries. Portable and inexpensive equipment is needed for easy and economical DNA quantification. Electrical bioimpedance spectroscopy (EBiS) is a non-invasive and inexpensive technique for examining the electrical properties of biological materials. The aim of this study was to explore a potential correlation between the measurement of total DNA extracted from human samples by UV-Vis spectrophotometry and EBiS. Hence, after quantifying the total DNA extracted from each sample by UV-Vis spectroscopy, EBiS was recorded and a possible correlation between the two measurements was analyzed. Considering the bioimpedance phase parameter at 5.24 MHz, a significant correlation was found with total DNA, especially when the concentration was below 100 ng/μL (Spearman coefficient = 0.82, p<0.005). Additional experiments are warranted to confirm these findings.

Biosensor of Inflammation Biomarkers Based on Electrical Bioimpedance Analysis on Immobilized DNA Without Chemical Modification

The development of biosensors to identify molecular markers or specific genes is fundamental for the implementation of new techniques that allow the detection of specific Deoxyribonucleic acid (DNA) sequences in a fast, economic and simple way. Different detection techniques have been proposed in the development of biosensors. Electrical Bioimpedance Spectroscopy (EBiS) has been used for diagnosis and monitoring of human pathologies, and is recognized as a safe, fast, reusable, easy and inexpensive technique. This study proves the development of a complementary DNA (cDNA) biosensor based on measurements of EBiS and DNA's immobilization with no chemical modifications. The evaluation of its potential utility in the detection of the gene expression of three inflammation characteristic biomarkers (NLRP3, IL-1β and Caspase 1) is presented. The obtained results demonstrate that EBiS can be used to identify different gene expression patterns, measurements that were validated by Quantitative Polymerase Chain Reaction (qPCR). These results indicate the technical feasibility for a biosensor of specific genes through bioimpedance measurements on the immobilization of cDNA.