When we receive samples in the Lab, one of the first steps we perform is DNA quantitation to determine the sample DNA concentration. We use Qubit 3.0 fluorometers and Qubit assays for this task.
The Qubit dsDNA BR (Broad Range) Assay Kit is designed to measure double-stranded DNA concentration in the range 100 pg/uL – 1,000 ng/uL, or a mass range of 2 – 1,000 ng. In practice, we generally use the BR assay kit to determine dsDNA concentration down to 1 ng/uL.
The Qubit dsDNA HS (High Sensitivity) Assay Kit is designed to measure double-stranded DNA concentration in the range 10 pg/uL – 100 ng/uL, or a mass range of 0.2 – 100 ng. In practice, we generally cut-over from the BR assay kit to the HS assay kit when dsDNA concentration is below 1 ng/uL.