Nanodiagnostics performed on human red blood cells with atomic force microscopy

Atomic force microscopy can yield valuable information concerning basic physical properties as well as alterations of human red blood cells. Erythropoietin is a hormone that is naturally produced in the kidney to stimulate the growth of red blood cells. Administration of genetically engineered synthetic erythropoietin stimulates the production of additional red blood cells. Therefore erythropoietin is used for blood doping in serious sports. The present study aims at investigating any differences in structure and stiffness of red blood cells which are produced body own or with synthetic erythropoietin. The samples are prepared via standard methods, and atomic force spectroscopy with trigger forces of three micronewtons is performed in ambient air. The penetration depth does not reveal statistically relevant differences in the two types of red blood cells. Furthermore, cells with a penetration depth four times as large as healthy ones are encountered in the samples of one donor. Subsequent medical examination revealed a rare type of diabetes. Atomic force spectroscopy shall serve as fast screening method for nanodiagnostics of diseases that alter surface nanomechanical properties.