Elemental analysis of cellular samples by in-air micro-PIXE

We developed a micro-PIXE system for the analysis of frozen cellular sample s at atmospheric pressure under helium gas cooling. We analyzed bovine aort ic endothelial (BAE) cells previously cultured in a medium containing bromo deoxyuridine (BrdU). It is known that these cells take BrdU into their nucl ei at the S phase of their metabolic cycle. We examined the Br uptake for i ncubation times of 6, 12 and 24 h, respectively. The Br maps showed an accu mulation in the nuclei and the Br concentration was found strongly dependen t on the incubation time. We have demonstrated that in-air micro-PIXE analy sis is a relevant technique for examining the molecular uptake in cells. (C ) 2001 Elsevier Science B.V. All rights reserved.