Pooling strategy for DNA extraction and PCR screening of smear-negative samples from Malawi. A total of 617 smear-negative samples were used for pooling based on the histology data from the Malawian IPTp effectiveness study. The histology-positive group including acute (A), chronic (C), and past infections (P) by histology was divided into 36 pools with 5 DBS samples per pool. The histology-negative (no infection by histology) group was divided into 44 pools with 10 samples in each pool. Several pools were short one or extra one sample to accommodate all available samples into pools. Five histology-negative samples (N) were processed in the smaller pools due to misclassification. After first round PCR screening, individual DBSs from positive pools were extracted, and second round PCR assays were performed.