34
Critical Qubit
™
Assay Considerations,
Continued
Assay
Temperature
The Qubit
™
assays were designed to be performed at room
temperature (22–28°C), and temperature fluctuations can influence
the accuracy of the assay. To minimize temperature fluctuations,
store all kit reagents at room temperature and insert all assay tubes
into the Qubit
®
2.0 Fluorometer only for as much time as it takes
for the instrument to measure the fluorescence, because the
Qubit
®
2.0 Fluorometer can raise the temperature of the assay
solution significantly, even over a period of a few minutes. Do not
hold the assay tubes in your hand before a measurement, because
holding the tubes warms the solution and results in a low reading.
Figure 2.
Effect of temperature on the Qubit
™
dsDNA BR assay. Qubit
™
dsDNA HS, Qubit
™
ssDNA, Qubit
™
RNA, Qubit
™
RNA BR, and Qubit
™
protein assays show similar sensitivities over the same range.
Incubation
Time
To allow the Qubit
™
assay to reach maximum fluorescence,
incubate the tubes for the DNA and RNA assays for 2 minutes
after mixing the sample or standard with the working solution.
After this incubation period, the fluorescence signal is stable for
3 hours at room temperature, for all nucleic acid assays except the
Qubit
™
ssDNA assay, which is stable for up to 30 minutes. The
Qubit
™
protein assay requires 15 minutes of incubation for a stable
signal. For greatest accuracy of the protein assay, the incubation
time of the samples should be within 10 minutes of the incubation
time of the standards.
Continued on next page
