Heparanase promoter is activated upon DTH elicitation. The ears of oxazolone-sensitized BALB/c mice (n = 3) were electroporated with Hpse-LUC (A, experimental group), CMV-LUC (B, control group), or Mut-Hpse-LUC (C, control group) reporter constructs. Left ears in both the experimental and control groups were challenged 24 hours later, while right ears remained untreated. Forty-eight hours after challenge, when a pronounced DTH reaction was noted in the left, but not right, ears of all mice (as judged by ear swelling and edema formation), the ears were resected, snap frozen, and lysed. Lysates were normalized for total protein content. Luciferase activity was determined as described in “Materials and methods” and expressed in relative units of light (RUL). Two independent experiments were performed, 3 mice per treatment.