design: Viral particle enrichment using 0.22 micrometer filtering nuclease treatment and viral nucleic acid extraction. SS3 RT condition 1 no Klenow no purification no purification no purification second strand synthesis SS3 RT condition 1 no Klenow no purification no purification no purification second strand synthesis SS3 RT condition 1 no Klenow no purification no purification no purification second strand synthesis SS3 RT condition 2 no Klenow no purification no purification no purification second strand synthesis SS3 RT condition 2 no Klenow no purification no purification no purification second strand synthesis SS3 RT condition 2 no Klenow no purification no purification no purification second strand synthesis SS3 RT condition 2 with Klenow no purification no purification no purification second strand synthesis SS3 RT condition 2 with Klenow no purification no purification no purification second strand synthesis SS3 RT condition 2 with Klenow no purification no purification no purification second strand synthesis SS3 RT condition 2 with Klenow with purification with purification with purification second strand synthesis SS3 RT condition 2 with Klenow with purification with purification with purification second strand synthesis SS3 RT condition 2 with Klenow with purification with purification with purification second strand synthesis SS4 RT condition 3 no Klenow no purification no purification no purification second strand synthesis SS4 RT condition 3 no Klenow no purification no purification no purification second strand synthesis SS4 RT condition 3 no Klenow no purification no purification no purification second strand synthesis SS4 RT condition 3 with Klenow no purification no purification no purification second strand synthesis SS4 RT condition 3 with Klenow no purification no purification no purification second strand synthesis SS4 RT condition 3 with Klenow no purification no purification no purification second strand synthesis SS4 RT condition 3 with Klenow with purification with purification with purification second strand synthesis SS4 RT condition 3 with Klenow with purification with purification with purification second strand synthesis