FIG. 1.

Sensitivity of DNA detection by Southern blot analysis after PCR of purified L. infantum DNA. Serial dilutions from 1 ng to 0.01 fg of purified L. infantum DNA were amplified by PCR, and products were analyzed by 2.5% agarose gel electrophoresis. Hybridization of the 116-bp amplified fragment was performed with a 70-bp labelled probe. Details of PCR amplification, sequence of primers, cloning, and sequencing of probe are given in the text. Lanes 1 to 9: 1 ng, 0.1 ng, 0.01 ng, 1 pg, 0.1 pg, 0.01 pg, 1 fg, 0.1 fg, and 0.01 fg, respectively, of DNA; lane 10, control without L. infantum DNA.