Numerical measures of two‐dimensional gel resolution and positional reproducibility

Procedures to measure two important properties of two‐dimensional electrophoresis systems have been developed. These procedures evaluate the overall resolution and positional reproducibility of two‐dimensional gel patterns. Using these measures we show that various state of the art gel systems can produce patterns exhibiting resolution measures of 15 000–50 000 (yielding practical upper bounds of about 2000–6000 detectable proteins in typical cellular samples) and that positional accuracy for most spots in gel‐to‐gel comparisons is better than a spot width (0.5–2.0 mm). Implemented as part of a computerized image analysis system for two‐dimensional gel data, these two measures can be used in the selection and optimization of gel systems, and in the selection of sets of well‐resolved, well‐matched spots for genetic and other quantitative sudies.