Results and Discussion
Figure 1 demonstrates the linearity of a dsDNA calibration curve. Abscissa data is reflective of measurements made with 1 cm pathlength; these measurements are considered actual dsDNA concentrations. Ordinate data reflects microvolume analysis obtained with the Take3 plate accessory using 2 µL sample volumes. Insert is an exploded view of the low dsDNA concentration calibration curve.
Excellent linearity is available over three orders of concentration magnitude. This dynamic range covers the expected concentrations of isolated dsDNA from genomic DNA isolation kits (20–200 ng/µL) and plasmid DNA isolation kits (500–2,000 ng/µL). The linear regression slope of 1.000 ±0.0038 to a 95% confidence limit can also be used as a measure of microvolume quantification accuracy relative to 1 cm pathlength measurements.
We have devised a method for the addition of 2 µL protein standards or unknown protein samples, followed by 2 µL BCA working reagent directly to the microspots of the Take3 plate accessory. Sixteen microspots on the plate allow for a six-point calibration curve in duplicate and four microspots for unknown samples.