Calcium content of individual, microscopic, (sub) nanoliter volume Paramecium sp. cells using rhenium-cup in-torch vaporization (ITV) sample introduction and axially viewed ICP-AES

The Ca content of individual Paramecium species (sp.) cells with an average volume of about 0.1 nL was determined by Re-cup in-torch vaporization (ITV) sample introduction and an axially viewed inductively coupled plasma atomic emission spectrometry (ICP-AES) system. Calcium contamination and, overall, sample preparation of live microscopic biological cells proved to be problematic. These problems were addressed using sub-boiled distilled, de-ionized, water, and by washing and manipulating cells under a microscope. Direct (i.e., minimum sample pre-treatment) Ca analysis of one microscopic cell at-a-time, and overall, an ability to discern small differences in the Ca content of individual cells are key advantages of this approach.