Gel filtration of P. falciparum cDNA. Lanes 1 and 2 represent end-modified cDNA, labeled with [α-32P] dATP (Amersham, Biosciences, UK), after gel filtration. To determine the average size of P. falciparum cDNA, size markers were synthesized by PCR utilizing primers specific for human erythrocyte α-spectrin (exon 2) and band 3 (exon 18 and 19) sequences (lanes 3 and 4). P. falciparum cDNA appears as a smear of an average size greater than 722 bp in length. cDNA and PCR products were evaluated using an 8 % denaturing polyacrylamide gel and autoradiography.