No evidence of HPV DNA in esophageal squamous cell carcinoma in a population of Southern Brazil

Figure 1 Analysis of DNA from esophageal tumor tissue for human papillomavirus using nested- polymerase chain reaction for human papillomavirus L1 gene. The MY09/11 primer pair was used in the first step (A) and the GP5/GP6 primer pair was used in the second step (B). 1: DNA size marker (100 bp DNA ladder); 2: Patient tumor DNA: [human papillomavirus (HPV)]-negative; 3: HPV DNA-negative control (Human Genomic DNA); 4: HPV DNA-positive control (cervicovaginal sample); 5: Negative control containing all polymerase chain reaction reagents except DNA.