The sequences of clones were subjected to blastn searches and aligned using clustalw (Thompson et al., 1994). The nucleotide sequences for the clones generated in this study were submitted to GenBank under the accession numbers FJ218151-FJ218162. The average mobility and SE of the mean of the mobilities of six isolates of both C. parvum and C. hominis were determined within a single run and across three runs. Microsoft excel was PR171 used to generate the average mobility, peak separation and SE of the means. A fragment of the 18S rRNA gene was amplified using genomic DNA from 10 recognized Cryptosporidium species and five cryptic species (Table 1). For all samples, PCR generated
clear products ranging from 289 to 296 bp when analyzed using agarose electrophoresis (data not shown). Optimal CE-SSCP conditions, in terms of the separation and sharpness of individual peaks, enabled the selection of standard conditions of 25 °C, 7% conformation polymer and capillary loading of 0.1–1 ng of sample for subsequent CE-SSCP
runs. Analysis of 18S rRNA gene amplicons from the Cryptosporidium samples using CE-SSCP resulted in defined peaks with mobilities ranging from 300 to 345 compared with the Liz500 internal standards (Table 2). There was some variation in sample mobility between runs, of between 2 and 10 U. Although the absolute mobility values differed slightly from run to run, the relative difference in the mobilities between different
samples was consistent for each species, and for multiple Roxadustat cell line Adenosine peaks where these occurred within a single sample. For example, the major peaks of C. parvum and C. hominis consistently migrated 6-bp apart in any run (Table 2). Despite between-run variation, apparent mobilities were consistent within and across runs for multiple isolates of C. parvum and C. hominis (Table 2). To control for run-to-run variation, C. parvum and C. hominis were used as reference control isolates in all CE-SSCP runs. The relative mobilities of CE-SSCP peaks from test samples were then calibrated to the apparent mobility of major peaks of C. parvum and C. hominis. These were set at 317 and 323 U, respectively. The mobility of the major peaks allowed Cryptosporidium species from within host groups to be discriminated. For example, the three species of most concern to humans, C. parvum, C. hominis and C. meleagridis, had major peaks at 317, 323 and 318, respectively (Table 2). The three species/genotypes from marsupials, C. fayeri, C. macropodum and the C. sp. possum genotype, could also be differentiated by the mobility of major peaks (Table 1). However, there was only a single unit difference in the mobilities between C. fayeri and C. macropodum from marsupials, and C. parvum and C. meleagridis from humans. The presence of two peaks provided an additional means of differentiation, making it possible to separate these species (Table 1).