A Sensitive, Nonradioactive Assay for Zn(II) Uptake into Metazoan Cells.

Sensitive measurements of cellular Zn(II) uptake currently rely on quantitating radioactive emissions from cells treated with Zn(II). Here, we describe a straightforward and reliable method employing a stable isotope to sensitively measure Zn(II) uptake by metazoan cells. First, biological medium selectively depleted of natural abundance Zn(II) using A12-resin [Richardson, C.

A Method for Selective Depletion of Zn(II) Ions from Complex Biological Media and Evaluation of Cellular Consequences of Zn(II) Deficiency.

We describe the preparation, evaluation, and application of an S100A12 protein-conjugated solid support, hereafter the "A12-resin", that can remove 99% of Zn(II) from complex biological solutions without significantly perturbing the concentrations of other metal ions. The A12-resin can be applied to selectively deplete Zn(II) from diverse tissue culture media and from other biological fluids, including human serum. To further demonstrate the utility of this approach, we investigated metabolic, transcriptomic, and metallomic responses of HEK293 cells cultured in medium depleted of Zn(II) using S100A12.