Using electrical impedance detection to evaluate the viability of biomaterials subject to freezing or thermal injury.

This paper is aimed at comprehensively investigating the dynamic low-frequency electrical impedance (DLFI) of biological materials during the processes of freezing, thawing and heating, and combinations of them. Electrical impedance detection (EID) was proposed as a means of rapidly evaluating the viability of biological materials subject to freezing or thermal injury (processes expected to be significant in the practices of cryobiology and hyperthermia). Using two experimental setups, the DLFI for selected biological materials (fresh pork and fish) under various freezing and heating conditions was systematically measured and analyzed. Preliminary results demonstrate that damage that occurs to a biological material due to freezing or heating could result in a significant deviation in its electric impedance value from that of undamaged biomaterials. Monitoring impedance change ratios under various freezing and heating conditions may offer an alternative strategy for assessing the amount of damage sustained by biomaterials subject to cryosurgery, cryo-preservation and hyperthermia. Implementation of the present method in order to develop a new micro-analysis or biochip system is also suggested.