Optimized sample preparation for high-resolution AFM characterization of fixed human cells.

Atomic force microscopy enables the simultaneous acquisition of high-resolution topographical and biophysical data allowing integrated analysis of cell surfaces during development and pathogenesis, and, critically, can link molecular and biophysical events. Here we used atomic force microscopy to analyse endometrial epithelial cells and neuronally differentiated P19 cells. Optimized reproducible sample preparation techniques enabled micro- and nanoscale multi-parameter analysis. Comparative analysis using atomic force microscopy and scanning electron microscopy demonstrated the utility of atomic force microscopy for examining tissue morphology, and its ability to generate data allowing differentiation of cells from different origins to be monitored. At low resolution atomic force microscopy produced topographic data complementary to scanning electron microscopy images, whilst at high resolution atomic force microscopy captured novel cell surface structural detail for both epithelial and neuronal cell types. Analysis of surface roughness provided biophysical data which enabled qualitative and quantitative differences between samples to be measured. This study provides an important optimization of sample preparation enabling more generalized atomic force microscopy utilization for cellular analysis required for advanced cell surface morphological studies.