The standard panel consists of two tape strips, panel 1, with 11 allergen patches and a negative control and panel 2, with 12 allergen patches. T.R.U.E. TestTM panels 1 and 2 contain 23 of the most frequent contact allergens. With the 23 allergens the test currently consists of, it is possible to detect about 60-70% of contact allergic reactions. Thus, there is a need for expanding the number of allergens included in T.R.U.E.Test in order to detect more contact allergic reactions. Bacitracin is one of these allergens, and the purpose of this study is to determine a concentration for the patch by using a bacitracin dilution series.