SYBR Green I | CAS 178918-96-2

SYBR Green I is a cyanine-based fluorescent nucleic acid stain that exhibits strong fluorescence enhancement upon binding to double-stranded DNA, making it widely used as a DNA-intercalating dye in fluorescence-based nucleic acid workflows. In real-time amplification and endpoint DNA quantification, the dye's DNA-dependent signal provides a convenient readout for nucleic acid abundance, while its compatibility with standard fluorescence instrumentation supports routine assay development in molecular biology and genomics research.

1. Real-Time PCR Quantification

SYBR Green I is routinely used in real-time PCR workflows to monitor DNA amplification by reporting fluorescence that increases as double-stranded DNA accumulates during cycling. Researchers and assay developers use it for gene expression studies, microbial load monitoring in research settings, and general-purpose quantification of PCR products when a sequence-specific probe is not required. Because the dye reports on dsDNA formation rather than a specific amplicon sequence, it is commonly paired with melting curve analysis to assess product uniformity and to help interpret amplification specificity in standard qPCR instrument platforms.

2. DNA Gel Staining And Imaging

SYBR Green I is also applied for post-run visualization of nucleic acids in agarose or polyacrylamide gel electrophoresis, where it stains dsDNA and enables fluorescence imaging of DNA bands. Molecular biology labs use it for routine checking of PCR products, restriction digests, plasmid preparations, and size/quality assessment of DNA fragments prior to downstream cloning or sequencing. The dye's strong dsDNA fluorescence response supports gel documentation workflows on common fluorescence gel imaging systems, facilitating rapid band detection with minimal handling compared to older staining approaches.

3. Endpoint DNA Quantification

SYBR Green I serves as a convenient fluorescence-based reagent for endpoint DNA quantification in microplate and cuvette formats, where dsDNA binding yields a measurable increase in signal proportional to DNA amount. Researchers use it for measuring DNA concentration in purification workflows, normalizing DNA inputs for library preparation development, and supporting routine quantification in nucleic acid research pipelines. In these applications, careful calibration with DNA standards and consistent assay conditions are typically used to translate fluorescence intensity into DNA concentration for experimental comparisons.

4. Nucleic Acid Binding Assays

SYBR Green I is frequently incorporated into fluorescence readouts for nucleic acid binding and DNA integrity studies, leveraging the dye's dsDNA-dependent fluorescence response as a proxy signal for DNA availability and structural state. Chemical biology and assay development teams use it to monitor changes in DNA conformation or accessibility that affect dye binding, supporting screening and characterization of DNA-interacting reagents in research workflows. This approach is commonly used alongside complementary analytical readouts to interpret how experimental conditions influence dsDNA content and fluorescence behavior.