The cost of malaria diagnosis of 96 blood spots with 10 positive samples (for species identification) using the single direct COX-III PCR (including only the single COX-III PCRs, PCR product purification and sequencing) can be up to a quarter of the cost when compared with the 18s-rRNA nested PCR (192 PCRs for genus diagnosis and 50 for species diagnosis) as described here, the COX-III PCR assay developed by Isozumi et al. [40], and a 18s-rRNA real time PCR strategy [39]. The gene discussed is MT-CO3; the disease is malaria.