The applicability of the semi-nested touchdown PCR was tested in ten samples of UTH milk from different brands commercialized in the state of Rio Grande do Sul (Southern Brazil). The procedure for the enumeration of total viable microorganisms in liquid UHT dairy products followed the method of the Normative Instruction Nr.62 of the Ministry of Agriculture of Brazil (MAPA) (Brasil, 2003). Briefly, samples of UHT milk were incubated at 37 for 7 days to observe visible changes, such as bloating and casting coagulation.