Semi-Automated Library Preparation for High-Throughput DNA Sequencing Platforms
Figure 1
The Parallel Semi-Automated Library Maker (PSALM) uses a NorDiag Magnatrix 8000 plus to prepare 32 samples simultaneously. DNA of 16 samples is sheared (1) and submitted to the automated steps of PSALM (Highlighted in Blue). After end-repair (2), and ligation of molecular barcoded adaptors (4), the 16 samples are pooled (6) and stored at or −. A new automated cycle is started to prepare additional 16 samples. After 12.08 hours, the 2 pools containing 32 samples enter the manual steps of PSALM for size selection in 6% PAGE gel (8), nick-translation, and PCR amplification (9). A final gel purification step is done in 4% Agarose gel for removing self-ligated adaptors. Next, the library is eluted from the gel using spin columns (11). Carboxy beads substitute for columns used in the manual library preparation to clean up enzymatic reactions (3, 5, and 10), and in the steps where DNA concentration is required (7). Thirty-two libraries are prepared to enter the sequencing pipeline in 16.08 hours. In contrast, only 4 samples are processed in parallel in the manual preparation. Spin columns are used in all purification steps (3, 5, 8 and 9), and a pool with only 4 barcoded libraries is obtained after 12.49 hours (11).
