Scanning transmission ion microscopy tomography at the Leipzig nanoprobe LIPSION

Scanning transmission ion microscopy (STIM) of joint cartilage Could visualise single collagen fibrils. Thus. answers to the controversial questions of their alignment could be given. However, the fibrils form three-dimensional structures that are not yet fully disclosed. STIM tomography is needed to give more detailed information. The size of the structures requires a challenging resolution of about 100 rim. The first STIM tomographic experiment has been performed at the Leipzig nanoprobe LIPSION. 360 projections of a cartilage sample (30 mum x 32 mum x 10 mum) were taken. The pixel resolution was 250 x 250 pixels for each projection. The data set was reconstructed at MARC Melbourne using the backprojection of filtered projections technique. The data show the feasibility of STIM tomography in cartilage research. However. experimental inaccuracies (rotational displacement and magnetic stray fields) have limited the resolution thus far. Improvements in the experimental set-up will lead to higher resolution. (C) 2002 Elsevier Science B.V. All rights reserved.