Figure 1. SDS-PAGE of purification steps of Taq DNA polymerase I enzyme. A 12% SDS-PAGE gel was used to analyze each step of the purification process. Lanes contain: 1) sonicated E. coli host cells not expressing Taq DNA pol I, 2) sonicated E. coli expressing Taq DNA pol I, 3) cell lysate cleared by thermal denaturation, 4) FPLC purified protein.