Salinity tracers

Yeo, A.R., Yeo, M.E., Caporn, S.J.M., Lachno, D.R. Flowers, T.J. (1985). The use of C-ethane diol as a quantitative tracer for the transpirational volume flow of water, and an investigation of the effects of salinity upon transpiration, net sodium accumulation and endogenous ABA in individual leaves of Oryza sativa L. Journal of Experimental Botany, 36, 1099-109. 

Fig. 6 Numerical simulation experiment with tracer. The Ebro River water is indicated by water with salinity equal to 0.1 psu and that of the Segre River equal to 0 psu...

The easiest technique fiar establishing the nonconservative behavior of an element, or one of its chemical species, is to compare its concentration to that of a conservative tracer. Salinity is typically used because it is a standard measurement performed on most seawater samples. 

Measurement of the serum concentrations of administered antibodies is a general tool to evaluate their persistence in circulation. This is usually performed by introducing a sufficient amount of the test antibody either by the intravenous or by the intraperi-toneal routes (see Note 3), in a quantity that can be easily detected and quantified in serum samples, even after a two log reduction in concentration. The antibody tracer can be labeled with radioisotope which permits direct quantification in serum samples. To minimize radioactive isotope use, we use an antibody tracer that is unmodified or labeled with biotin or other derivation chemistries, and then determine its serum concentrations by ELISA techniques. We commonly inject 100 xg of the test antibody in a 200 xl volume of phosphate-buffered saline into each mouse intraperitoneally (i.p.) (see Note 4). This amount can vary depending on the goals of the experiment and the sensitivity of the detection method. A minimum of five inbred mice, sex-matched and age-matched, at 8-16 weeks of age are recommended for each antibody to be tested. 

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