Figure 4. Polymerase chain reaction amplification of the partial vanHAX clusters from DNA extracted from animal feed–grade avoparcin and the antibiotic producer Amycolatopsis coloradensis NRRL 3218, and genes vanH, ddlN, and vanX from DNA extracted from animal feed grade avoparcin. M: 1 kb plus DNA ladder. Lanes 1–2: the partial van cluster (2.3–2.4 kb) amplified with primers vanH‑1 and vanX‑4; lane 1: DNA extracted from animal feed grade avoparcin; lane 2: DNA of the avoparcin producer A. coloradensis NRRL 3218. Lane 3: vanH (500 bp) amplified with primers vanH‑1 and vanH‑2. Lane 4: ddlN (850 bp) amplified with primers ddlN‑2 and ddlN‑3. Lane 5: vanX (500 bp) amplified with primers vanX‑3 and vanX‑4.