EDTA binds to DEAE-cellulose columns and salt-eluted fractions may contain as much as 20 times the original concentration of EDTA. If not corrected for, this high concentration of EDTA will interfere with three of the most frequently used protein assays. The errors encountered were reductions in apparent protein concentration of 50% as measured by the Lowry assay, 25% by the biuret determination, and as much as 90% by the spectrophotometric method. The mechanisms for these interferences appear to be chelation of copper by EDTA, in the case of the Lowry and biuret assays, and differential absorption of ultraviolet light by EDTA in the spectrophotometric case. Several possible methods for overcoming these interferences are discussed.
|Original language||English (US)|
|Number of pages||9|
|State||Published - Nov 1972|
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology