Invitrogen™ Quant-iT™ dsDNA Assay Kits, high sensitivity (HS) and broad range (BR)

Product Code.	Assay	Quantitation Range	unitSize
10555213	dsDNA Quantitation, BR	4 to 1000 ng	1 set
10164582	dsDNA Quantitation, HS	0.2 to 100 ng	1 set

Product Code. 10555213 Supplier Invitrogen™ Supplier No. Q33130

Description

For highly selective quantitation of double-stranded DNA over RNA, the Quant-iT dsDNA Assay Kits, high sensitivity and broad range, produce fluorescence signals that are linear in the ranges of 0.2-100 ng and 2-1000 ng of DNA, respectively.

Perform dsDNA quantification easily and quickly with Quant-iT dsDNA assay kits. Both the Quant-iT High-Sensitivity dsDNA Assay Kit and the Quant-iT Broad-Range dsDNA Assay Kit provide concentrated assay reagent, dilution buffer, and pre-diluted DNA standards. These DNA assay kits are highly selective for double-stranded DNA over RNA, and, in the ranges of 0.2–100 ng DNA (for the HS dsDNA Assay Kit) and 4–1000 ng DNA (for the BR dsDNA Assay Kit), the fluorescence signal is linear.

The Quant-iT dsDNA High-Sensitivity Assay Kit and the Quant-iT dsDNA Broad-Range Assay Kit make DNA quantification easy and accurate. The kits provide concentrated assay reagent, dilution buffer, and prediluted DNA standards. Simply dilute the reagent 1:200, load 200 μL into the wells of a microplate, add 1–20 μL sample, mix, then read the fluorescence.

The assays are highly selective for double-stranded DNA over RNA, and, in the range of 0.2–100 ng for the HS assay or 4–1000 ng for the BR assay, the fluorescence signal is linear with DNA. The assays are performed at room temperature, and the signal is stable for three hours. Common contaminants such as salts, solvents, detergents, and protein are well tolerated in these assays.

Order Info

Shipping Condition: Room temperature

Specifications

• Assay: dsDNA Quantitation, BR
• Detection Method: Fluorescence
• For Use With (Equipment): Microplate Reader
• No. of Reactions: 1000 Assays (200 μL assay volume)
• Quantitation Range: 4 to 1000 ng
• Product Line: Quant-iT
• Quantity: 1 kit
• Shipping Condition: Room Temperature

Frequently Asked Questions (FAQs)

Why am I getting negative fluorescence values with my Qubit Assays?

Negative fluorescence is a physical impossibility. It is an artifact from software autocorrecting for background signal. This means your reader is picking up and subtracting out background light at the cost of your data. Make sure to do a buffer-only control and assess the type of signal. You may need to switch to a different plate.

I have a Quant-iT DNA Kit and want to use it for the Qubit Fluorometer. Can I?

Yes, the manual has directions for this application. You will use the 0 ng/µL lambda dsDNA HS standard to generate Standard #1. You will prepare a dilution of the 10 ng/µL lambda dsDNA HS standard to generate Standard #2. You then prepare the samples and compare them to this 2-point standard curve. The Quant-iT dsDNA BR Kit can be used in a similar manner.

What is the useful pH range for Quant-iT DNA kits?

The buffer included in the kit should assure the proper pH range, even if your DNA is at a pH outside of this range, since at least a 10-fold excess of kit buffer over sample is used in the assay.

I'm trying to quantify some DNA labeled with a fluorophore. Will this work?

PicoGreen dye and other fluorescence-based quantification reagents are not recommended for quantifying dye-conjugated nucleic acids. The attached dye molecules can interfere with either binding and/or fluorescence output of the quantification reagents.

Does DNA length have an effect on the dsDNA assays?

Strands that are roughly in the 20-mer range or shorter show a lower level of signal. For dsDNA samples that are composed of mostly short strands, the reagent may still be used, but one should use a dsDNA standard that is of comparable length as the sample.

What is the difference between the Quant-iT PicoGreen DNA, Quant-iT DNA, and Qubit DNA assays?

The Qubit Fluorometer contains highly optimized algorithms that calculate the concentration of the sample using either the Qubit assays or the Quant-iT DNA assays. The Quant-iT PicoGreen DNA assay may be adapted to the Qubit Fluorometer using the MyQubit firmware. The performance of all of these assays is similar.

The Quant-iT PicoGreen DNA assay is the most established assay and the most general-purpose (http://tools.thermofisher.com/content/sfs/manuals/PicoGreen-dsDNA-protocol.pdf). It requires the dilution of the standard DNA and buffer but can be adapted for use with either cuvettes, microplates, or the NanoDrop 3300.

The Quant-iT DNA assays provide a ready-to-use buffer and pre-diluted standard DNA for analyzing a large number of samples (>20 samples) using a 96-well microplate with no further adaptation.

The Qubit assays (https://www.thermofisher.com/us/en/home/industrial/spectroscopy-elemental-isotope-analysis/molecular-spectroscopy/fluorometers/qubit/qubit-assays/myqubit.html) are intended for low throughput (<20 samples), and are only used on the Qubit Fluorometer.

Can I make my own assay for the Qubit Fluorometer?

Yes, you can, for Qubit instruments developed after the original Qubit (1.0) Fluorometer. See MyQubit assay instructions here (http://www.thermofisher.com/us/en/home/life-science/laboratory-instruments/fluorometers/qubit/qubit-assays/myqubit.html.html).

I have a crude lysate. Will the Quant-iT and Qubit assays work?

Generally, the cleaner the sample the better. Some salts, proteins, and detergents are tolerated in the assays; see the specific assay protocol for which ones and at what concentrations.

How does the accuracy and sensitivity of the Qubit quantitation assays using the Qubit fluorometer compare to a microplate reader?

The accuracy and sensitivity of the Qubit quantitation assays are the same as that of a microplate reader. This was a requirement during product development. The detection limits for each Qubit kit can be found on the corresponding product manual, which can be found by searching our website by keyword or catalog number.

Can the Qubit kits give an indication of sample quality in nucleic acid samples?

No. The Qubit DNA and RNA kits only quantify the amount of either DNA or RNA in the sample. The Qubit fluorometer cannot take absorbance readings to provide a A260/A280 ratio or detect protein in nucleic acid samples. This can be done with the NanoDrop instrument. If your sample contains protein or other contaminants that can affect the assay, it should be further purified.

If your sample may contain both DNA and RNA, one may use either (or both) the DNA and RNA Qubit kits and compare with samples treated with either RNase or DNase to get an accurate determination of DNA or RNA, respectively.

Can I use the Quant-iT and Qubit Kits with other fluorometers?

All Quant-iT and Qubit kits are compatible with all fluorometers and microplate readers that have the appropriate light sources and filters. You won't have access to the algorithm in the Qubit fluorometer for generating the standard curve provided by the instrument, instead, you must make a few dilutions of the highest standard DNA or RNA (Standard #2) in the Qubit kits to generate a standard curve with multiple data points.

Can I use the original Quant-iT Kits with the Qubit Fluorometer?

No, we do not recommend this. Some of the dyes in the original Quant-iT kits (those NOT listed as “for use with the Qubit fluorometer”) are not compatible with the Qubit Fluorometer. In addition, the new Quant-iT kits (labeled as “for use with the Qubit Fluorometer”) have standards formulated to be compatible with the Qubit fluorometer internal algorithms for the respective assays. The Qubit Fluorometer-compatible kits are also less expensive per assay if you are processing fewer than 20 samples at a time.

How can I calculate my unknown samples' concentration using the Quant-iT dsDNA Assay Kit, broad range (Cat. No. Q33130)?

To calculate your sample concentration using the Quant-iT dsDNA Assay Kit, broad range, first measure your standards to create the standard curve. Then run your unknown samples to determine the amount of DNA or RNA (ng) and divide that DNA or RNA amount by the amount of sample volume added into the well.
This calculation will be correct as long as the concentration range of the samples fall within the kits' suggested range.

What is the shelf life of Quant-iT dsDNA Assay Kit (Cat. No. Q33130, Q33120)?

We have tested all of the Qubit/Quant-iT kits for 6 months of stability, when stored appropriately.