Artifacts in magnetic force microscopy of histological sections

Abstract

Detection of iron-oxide nanoparticles in biological samples has widespread applications. Iron can be naturally present in biological tissues as physiological ferrihydrite particles of ferritin(iron) or as biogenic magnetite nanoparticles in certain neurodegenerative pathologies. In our previous studies, we had reported how magnetic force microscopy (MFM) can be used to map iron deposits in tissue sections in a label-free manner. In this study, to improve the efficiency of MFM for histological analysis, we explored the effect of increasing scan rate. Our results show how MFM images of tissue sections can be contaminated with artifacts due to topographical cross-talk, especially at higher scan rates. These artifacts were observed in rodent spleen as well as in sections of brain tissue obtained from patients with Alzheimer’s Disease. Our results show how topographical cross talk can make it challenging to unambiguously detect histological iron via MFM. Multimodal approaches can help overcome some of these limitations.