# Key Points from DNA Synthesis and Lab Automation Discussions

• Researchers discussed G-protein coupled optogenetics, noting its relatively slow operational timescale of seconds compared to other optogenetic techniques, highlighting the technical limitations of current neurostimulation methods.

• The conversation extensively covered DNA oligonucleotide synthesis methods, particularly inkjet-based approaches using phosphoramidite chemistry, with detailed analysis of droplet sizes (ranging from 1.5 to 60 picoliters) and spot diameters (approximately 50-115 microns).

• Technical challenges in DNA synthesis were examined, including the critical 2% failure rate per synthesis step, the need for excess reagents to ensure high yield (>99.9%), and the importance of proper surface chemistry to prevent deletion mutations.

• The POSaM (Piezoelectric Oligonucleotide Synthesizer and Microarrayer) system was analyzed in detail, with participants noting its synthesis cycle of printing, washing, oxidation, washing, detritylation, and washing steps.

• Surface preparation techniques were discussed, with the discovery that Rain-X (a hydrophobic silane) creates effective virtual wells on glass slides that maintain integrity during the synthesis process.

• Cost considerations for DNA synthesis were shared, with reagent costs estimated at under $50 per slide according to an NCBI publication, though professional-grade equipment for precise droplet placement was noted to cost $20,000-$50,000.

• Resources on lab automation were shared, including documentation for building a respirometer using FSM, Tcl and Arduino, and a list of lab devices with RS232 interfaces that could be integrated into automated systems.