Figure 2From: Long-term storage limits PCR-based analyses of malaria parasites in archival dried blood spots Efficiency of the PCR assay based on the ssrRNA genes when applied to template purified by Chelex (C) vs Qiagen (Q) from dried blood spots collected between 1998 and 2009 that were confirmed by microscopy to be positive for Plasmodium falciparum . Back to article page