Description

Low-concentration double-stranded DNA samples can be difficult to quantify using traditional UV A260 measurements. The StarLighter dsDNA HS Assay Kit provides a high-sensitivity, fluorescence-based method for selective quantification of double-stranded DNA. The assay detects initial dsDNA concentrations from 5 pg/µL to 120 ng/µL, depending on sample volume, with a total assay range of 0.1–120 ng.

The kit contains a fluorescent reagent, assay buffer, and two dsDNA standards. It provides high selectivity for dsDNA over RNA and tolerates specified concentrations of common laboratory contaminants, including salts, free nucleotides, solvents, detergents, and proteins.

The protocol supports two measurement formats. Samples can be measured individually using a Qubit fluorometer and 0.5 mL thin-walled clear analysis tubes, or processed in a black 96-well microplate using a fluorescence microplate reader. Each assay accepts 1–20 µL of sample in a final reaction volume of 200 µL.

The working solution is prepared by diluting dsDNA HS Fluorescent Reagent QF into dsDNA HS Buffer QB at a 1:199 ratio. After mixing, the reaction requires a 2-minute incubation at room temperature while protected from light. The fluorescent signal remains stable for up to 3 hours after incubation when protected from light.

The StarLighter dsDNA HS Assay Kit is available in 20-reaction and 500-reaction formats. This product is for research use only and is not intended for diagnostic or therapeutic procedures.

Specification

Product Name	StarLighter dsDNA HS Assay Kit
Target	Double-stranded DNA (dsDNA)
Detection Method	Fluorescence-based quantification
Initial dsDNA Concentration Range	5 pg/µL–120 ng/µL, depending on sample volume
Total Assay Range	0.1–120 ng
Sample Volume	1–20 µL
Final Reaction Volume	200 µL
Working Solution Ratio	1 part dsDNA HS Fluorescent Reagent QF to 199 parts dsDNA HS Buffer QB
Standards	QS0: 0 ng/µL; QS1: 10 ng/µL
Assay Temperature	20–25°C
Incubation Time	2 minutes at room temperature, protected from light
Signal Stability	Up to 3 hours after incubation when protected from light
Compatible Instruments	Qubit fluorometer or fluorescence microplate reader
Microplate Reader Settings	Excitation: 485 nm; Emission: 530 nm
Shipping Condition	Ship on ice
Storage	2–8°C upon arrival; protect fluorescent reagents from light
Available Sizes	20 reactions and 500 reactions
Intended Use	For research use only

Catalog Numbers and Kit Components

Component	FS-T1001-S 20 Reactions	FS-T1002 500 Reactions
dsDNA HS Buffer QB	10 mL	250 mL
dsDNA HS Standard QS0 (0 ng/µL)	200 µL	5 mL
dsDNA HS Standard QS1 (10 ng/µL)	200 µL	5 mL
dsDNA HS Fluorescent Reagent QF	50 µL	1.25 mL

Required Materials Not Supplied

Fluorometer and 0.5 mL thin-walled clear analysis tubes, or a fluorescence microplate reader and black 96-well microplates
Vortex mixer
Pipettes and sterile, nuclease-free pipette tips
Nuclease-free water or TE buffer for sample dilution, if required

Features

High-sensitivity dsDNA quantification: Detects initial dsDNA concentrations from 5 pg/µL to 120 ng/µL, depending on sample volume.
Defined total assay range: Measures 0.1–120 ng of dsDNA per assay.
Selective fluorescence measurement: Provides high selectivity for double-stranded DNA over RNA.
Low sample requirement: Supports sample volumes from 1 to 20 µL.
Two measurement formats: The protocol can be performed using a Qubit fluorometer or a fluorescence microplate reader.
96-well assay format: Supports fluorescence-based dsDNA quantification in black-wall, clear-bottom 96-well microplates.
Short incubation: Requires a 2-minute incubation at room temperature while protected from light.
Stable post-incubation signal: The fluorescent signal remains stable for up to 3 hours when protected from light.
Two supplied standards: Includes QS0 at 0 ng/µL and QS1 at 10 ng/µL.
Two package sizes: Available as FS-T1001-S for 20 reactions and FS-T1002 for 500 reactions.

Documented Contaminant Tolerance

The following table lists the contaminant concentrations evaluated in the assay. Results reported as “OK” usually produced less than 10% perturbation under the stated conditions.

Contaminant	Final Concentration in Assay	Approximate Concentration in 10 µL Sample	Result
BSA	10 mg/mL	200 mg/mL	OK
Sodium acetate	20 mM	400 mM	OK
Ammonium acetate	20 mM	400 mM	OK
Sodium chloride	20 mM	400 mM	OK
Magnesium chloride	5 mM	100 mM	OK
Phenol	0.1%	2%	OK
Chloroform	0.5%	10%	OK
Ethanol	0.5%	10%	OK
SDS	0.01%	0.2%	OK
Triton X-100	0.01%	0.2%	OK
ssDNA	1×	1×	OK
PEG	1%	20%	OK
RNA	1×	1×	OK
dNTPs	100 µM	2 mM	OK

Application

The StarLighter dsDNA HS Assay Kit is intended for fluorescence-based quantification of double-stranded DNA using either a Qubit fluorometer or a fluorescence microplate reader.

Qubit Fluorometer Assay Format

Equilibrate all kit components to room temperature.
Prepare the working solution by combining dsDNA HS Fluorescent Reagent QF and dsDNA HS Buffer QB at a 1:199 ratio.
Use thin-walled, clear 0.5 mL PCR tubes.
Add 190 µL of working solution and 10 µL of standard to each standard tube.
Add 180–199 µL of working solution and 1–20 µL of sample to each sample tube.
Ensure that the final volume in every tube is 200 µL.
Vortex for 3–5 seconds without creating bubbles.
Incubate for 2 minutes at room temperature while protected from light.
Read the standards and samples using the applicable instrument procedure.

Calibration requires two standards. Standard QS0 is used at 0 ng/µL, and Standard QS1 is used at 10 ng/µL. A new calibration is strongly recommended for every new assay run, and calibration curves from other kits must not be used.

Fluorescence Microplate Reader Assay Format

Equilibrate all kit components to room temperature and mix thoroughly by vortexing.
Prepare the working solution using a 1:199 ratio of QF fluorescent reagent to QB buffer.
Dispense 190 µL of working solution into standard wells.
Dispense 180–199 µL of working solution into sample wells according to the sample volume.
Prepare standards from 0 to 10 ng/µL by serially diluting Standard QS1.
Add 10 µL of each standard and 1–20 µL of each sample to the designated wells.
Ensure that the final volume in each well is exactly 200 µL.
Mix the plate for 10–15 seconds.
Incubate for 2 minutes at room temperature while protected from light.
Set the fluorescence microplate reader to 485 nm excitation and 530 nm emission.
Read the standards and samples, generate a standard curve, and calculate the concentrations of the unknown samples.

Black-wall, clear-bottom microplates are specified for the 96-well format to minimize cross-talk. Samples exceeding the linear range should be diluted and measured again.

FAQ

What is the StarLighter dsDNA HS Assay Kit used for?

The kit is used for high-sensitivity, fluorescence-based quantification of double-stranded DNA. It provides high selectivity for dsDNA over RNA and supports initial sample concentrations from 5 pg/µL to 120 ng/µL, depending on sample volume.

What is the dsDNA quantification range?

The total assay range is 0.1–120 ng. Depending on the sample volume, the supported initial dsDNA concentration range is 5 pg/µL–120 ng/µL.

How much sample is required per reaction?

Each reaction uses 1–20 µL of sample. Working solution is added to produce a final reaction volume of exactly 200 µL.

Can the kit be used with a Qubit fluorometer?

Yes. The user guide provides a Qubit fluorometer protocol using thin-walled, clear 0.5 mL PCR tubes, two supplied standards, and a 200 µL final assay volume.

Can the kit be used with a 96-well fluorescence microplate reader?

Yes. The protocol supports black-wall, clear-bottom 96-well microplates. The specified reader settings are 485 nm excitation and 530 nm emission.

How long is the incubation time?

The assay requires a 2-minute incubation at room temperature while protected from light. The fluorescent signal remains stable for up to 3 hours after incubation when protected from light.

Which kit sizes and catalog numbers are available?

FS-T1001-S contains reagents for 20 reactions. FS-T1002 contains reagents for 500 reactions.

How should the StarLighter dsDNA HS Assay Kit be shipped and stored?

The kit should be shipped on ice and stored at 2–8°C upon arrival. Fluorescent reagents must be protected from light to prevent signal decay.

dsDNA HS Assay Kit——StarLighter