Variation of B1 gene and AF146527 repeat element copy numbers according to Toxoplasma gondii strains assessed using real-time quantitative PCR.

Using the multicopy B1 gene and AF146527 element for the amplification of Toxoplasma gondii DNA raises the issue of reliable quantification for clinical diagnosis. We applied relative quantification to reference strains using the single-copy P30 gene as a reference. According to the parasite type, the copy numbers for the B1 gene and AF146527 element were found to be 5 to 12 and 4 to 8 times lower than the previous estimations of 35 and 230 copies, respectively.