Table 1. Evaluation of plasmid DNA recovery using DNeasy DNA extraction columns or direct DNA extraction in situ.

			Recovered plasmid copies
DNA extraction method	Cell count	Spiked plasmid copies	Replicate 1	Replicate 2	Average recovered plasmid copies	% Recovery
DNeasy Blood & Tissue	1.00 × 106	1.33 × 106	3.43 × 105	6.35 × 105	4.89 × 105	36.8
	2.50 × 105	1.33 × 106	1.02 × 106	3.95 × 105	7.08 × 105	53.2
	6.25 × 104	1.33 × 106	1.44 × 106	1.49 × 106	1.46 × 106	110
	1.56 × 104	1.33 × 106	1.61 × 106	1.73 × 106	1.67 × 106	126
in situ	~1.60 × 105	1.33 × 106	1.23 × 106	1.25 × 106	1.24 × 106	93.5

Plasmid DNA of known concentration was added to the indicated number of 293T-MLV-DCSIGN assay cells in duplicate (replicates 1 and 2). DNA was extracted using the DNeasy Blood & Tissue kit or 96-well in situ DNA extraction method, and qPCR performed to detect the plasmid spike. % yield is expressed relative to the number of spiked plasmid copies and reflects the average yield of the two replicates. Cell count for the in situ DNA extraction method was estimated based on one cell doubling between cell seeding and DNA extraction.