Figure 2. Means and two standard errors of the mean error bars for pairwise comparisons among 116 12-banded H37Rv lanes show that error is consistently larger when comparing lanes between gels than when comparing lanes from the same gel. The x-axis corresponds to w(b), and the y-axis to d(b), as presented in the text. It is evident that error is proportional to fragment length in the range of fragment lengths found in H37Rv. The data exhibit 2% to 3% error for between gel comparisons, but only approximately 1% error on average for within gel comparisons.