Measurement of the rate of uptake and subcellular localization of porphyrins in cells using fluorescence digital imaging microscopy.
A fluorescence imaging system incorporating a cooled slow-scan charge-coupled device camera was used to study the rate of uptake and subcellular localization of prophyrins in living cells. Measurements were carried out on human dermal fibroblasts (D532) using two different prophyrins meso-tetra(4-N-methylpyridyl)porphine (TMPP) and meso-tetra(4-N-hexylpyridyl)porphine (THPP). It was observed that TMPP was rapidly taken up by cells and principally located in the nucleus. The THPP, on the other hand, internalized more slowly and exhibited a particulate distribution in the cytoplasm.