experimental research that involves the manipulation of variables. The paper presents experimental research that involves the manipulation of variables. The variables are measured, calculated, and compared to establish their relationships or effect. The research is also experimental because it is performed in a controlled environment which is a lab. In this experimental research, the authors present a practical PCR-based H-typing system and H-genotyping PCR for E. coli. Additionally, they involve various materials and methods in the experiment. For example, the methods and experiments include source sequences, sequence comparison, bacterial strains, simplex PCR, as well as multiplex PCR. From the experiment, the results indicate that, however, serotyping is a standard technique for subtyping the isolates of pathogenic E. coli, the clumping
