FIG. 1.

Analytical sensitivity of nested PCR for detection of E. chaffeensis 16S rRNA genes in Chinese ticks. Lanes M, molecular standards. Sizes (in base pairs) are indicated on the left. (A) Products of the primary amplification using serial dilutions of plasmids containing the E. chaffeensis 16S rRNA gene as templates. Lanes 1 through 7, template copy numbers of 8 × 10⁴, 8 × 10³, 8 × 10², 80, 8, 4, and 2, respectively. Lane 8, negative (water) control. The expected size of the primary amplified product is 587 bp. (B) Products of the nested PCR using 1 μl of the corresponding primary product as the template. The expected product size is 389 bp.