Nucleic Acid Quantification

dsDNA Assays

---

Helixyte™ Green Fluorimetric dsDNA Assay Kits (Cat# 17650 & 17651) simplify DNA quantification without sacrificing sensitivity. The assay provides a linear detection range between 0.2 ng and 1000 ng double-stranded DNA (dsDNA) (Figure 1.). The high-sensitivity DNA assay is ideal for quantifying PCR products, viral DNA, DNA fragments for subcloning and other applications requiring small amounts of DNA. Helixyte™ Green Fluorimetric dsDNA Assay Kits are highly selective for dsDNA over RNA and other common contaminants, including free nucleotides, salts, solvents and proteins. The Helixyte™ Green assay is an excellent replacement for PicoGreen^®-based DNA assays.

Helixyte™ Green dsDNA Quantifying Reagent (Cat# 17597) can accurately quantify as little as 100 pg/mL of dsDNA using a fluorometer or 300 pg/mL using a fluorescence microplate reader. Helixyte™ Green dsDNA quantification assay is 10,000 times more sensitive than conventional UV absorbance measurements at 260 nm and at least 400 times more sensitive than the Hoechst 33258 dye based assay. Helixyte™ Green dsDNA Quantifying Reagent shows >1000-fold fluorescence enhancement upon binding to dsDNA, and much less fluorescence enhancement upon binding to single-stranded DNA (ssDNA) or RNA, making it possible to quantify dsDNA in the presence of equimolar amounts of ssDNA, RNA or proteins. Helixyte™ Green dsDNA Quantifying Reagent shows little if any AT- or GC-selectivity, enabling accurate DNA quantification.

 

RNA Assays

---

StrandBrite™ Green Fluorimetric RNA Quantitation Kit (Cat# 17655) provides a homogeneous assay for quantifying RNA in the presence of DNA. This RNA assay exhibits a linear detection range between 5 ng and 100 ng RNA (Figure 2.). Assay linearity is maintained even in the presence of several interfering compounds commonly found in nucleic acid preparations, including salts, urea, ethanol, chloroform, detergents, proteins and agarose. Its relatively high selectivity for RNA over dsDNA enables accurate RNA quantification in the presence of DNA and other common contaminants, including free nucleotides, salts, solvents and proteins, making this assay ideal for measuring samples for microarray, RT-PCR and northern blot procedures.

StrandBrite™ Green Fluorimetric RNA Quantitation Kit allows detection of as little as 10 ng/mL RNA with a standard fluorometer, fluorescence microplate reader or filter-based fluorometer using standard fluorescein excitation and emission settings. The sensitivity is at least 20-fold better than that achieved with ethidium bromide and at least 100-fold better than that achieved using conventional absorbance measurements at 260 nm. Unlike UV absorbance measurements at 260 nm, StrandBrite™ Green RNA Quantifying Reagent (Cat# 17610) does not detect significant sample contamination caused by free nucleotides. Thus, StrandBrite™ Green RNA Quantifying Reagent more accurately measures the amount of intact RNA polymers in potentially degraded samples.