DNA methylation and quantitative analysis of B19V nucleic acids in a time course of infection.

UT7/EpoS1 and U937 cells were infected with B19V at a multiplicity of infection of 103 geq/cell, and samples collected from 0 to 27 days post infection (dpi). Quantitative analysis was carried out for the determination of the amounts of viral DNA and total viral RNA from cell fractions (copies/104 cells). Methylation index was calculated by parallel amplification with both MSP primer pairs on bisulfite-modified DNA and is expressed as ratio of methylated over total viral DNA. ND: not detected.