Qubit Assays

Qubit assays are available for double- and single-stranded DNA (dsDNA and ssDNA), RNA, microRNA, and protein. Qubit DNA and RNA assays are available with different quantification ranges. The HS (high sensitivity) assays quantitate the lowest levels of analyte, the BR (broad range) assays do so across a wider range, and the RNA XR (extended range) assay is ideal for abundant samples. These various detection ranges allow accurate measurement across a wide range of concentrations. As the graph shows, both Qubit HS and BR assays detect lower levels of analyte than UV absorbance.

Our Qubit dsDNA high-sensitivity (HS) and broad-range (BR) assays are highly selective for dsDNA over RNA and ssDNA. The high-sensitivity assay is designed for samples with low concentrations of dsDNA, which helps to conserve precious samples. Common contaminants such as salts, free nucleotides, RNA, solvents, detergents, or protein are well tolerated in the dsDNA HS and BR assays.

In this test, accuracy and precision were assessed on the Qubit 4 and Flex Fluorometers, as well as a competitor’s instrument, using the Qubit dsDNA HS and BR assays. Percent deviation and CV were both lower for the Qubit 4 and Flex instruments than the competitor’s, demonstrating higher accuracy and precision.

Qubit 1X dsDNA assays are provided in a convenient pre-mixed format that eliminates the step of preparing the Qubit working solution. Simply add your sample or standard to the premixed solution, incubate, and read your results. This format offers a simplified, faster workflow while reducing the number of tubes in the kit (and therefore the amount of plastic used).

The Qubit 1X dsDNA HS assay provides the same dynamic range and limit of detection as the standard dsDNA HS assay, while the Qubit 1X dsDNA BR assay has a higher dynamic range than the standard dsDNA BR assay, achieving 4,000 ng/µL in the extended range.

In this test of the Qubit 1X dsDNA HS (left) and BR (right) assays over their core ranges, the measured amount of dsDNA deviated from the expected value by less than 10%, even in the presence of equal amounts of RNA.

The Qubit ssDNA Assay Kit is designed to quantify long ssDNA or oligonucleotides. Purify ssDNA before performing the assay, as it can also detect dsDNA and RNA. However, assay results will not be affected by common contaminants such as salts, short oligonucleotides (≤6 bases), free nucleotides, solvents, detergents, or protein.

To quantify RNA, you can choose among three Qubit RNA Assay kits with overlapping ranges of initial sample concentrations, from as little as 250 pg/μL to 10,000 ng/μL. These kits are highly selective for RNA over double-stranded DNA (dsDNA). Unlike other RNA assays, they do not require DNase for an accurate measurement, even if DNA is present in the sample. Common contaminants such as salts, free nucleotides, solvents, detergents, or proteins are well tolerated in these assays.

In this sensitivity test, both the Qubit RNA and microRNA assays (red and blue bars) measured very close to the actual concentrations of their target RNAs (red and blue lines).

The Invitrogen Qubit microRNA Assay Kit is designed for easy and accurate quantification of small RNA (17–25 nt or bp) such as microRNA, even in the presence of common contaminants such as salts, free nucleotides, solvents, detergents, and protein. The assay is highly selective for small RNA over rRNA or large messenger RNA (mRNA) (>1,000 bp).

Small RNA in pure samples has reproducibly been quantified at levels as low as 0.5 ng in the assay tube. The assay detects all types of small RNA, including microRNA and short interfering RNA (siRNA), both single- and double-stranded. Because it does not detect nucleotides, it can distinguish small mRNA particles from completely degraded RNA.

MyQubit assays bring customized fluorescence assays right to your benchtop, providing a reliable platform for many quantitation needs, from laboratory research and quality control to process monitoring and beyond. You can add new assays to your Qubit 3.0 and 4 Fluorometer via simple download and transfer of .qbt files using a USB drive.

As examples of the kinds of custom MyQubit assays you can create, we have developed new MyQubit assays for several commonly quantitated analytes using Amplex Red reagents. When you transfer the assay .qbt files to your Qubit Fluorometer via a USB drive, they will be available alongside the factory-loaded Qubit assays, extending the capabilities of your Qubit Fluorometer.

For Research Use Only. Not for use in diagnostic procedures.