Micro Volume Quantitation Measurement of Nucleic Acid using Nano Stick with UV-1280

Significance of the Topic

Accurate quantitation of nucleic acids in micro-volumes is essential in molecular biology research, clinical diagnostics and quality control. Conventional cuvettes require larger sample volumes and extensive cleaning, increasing risk of carryover and limiting throughput. A reliable micro-volume system improves efficiency, conserves precious samples and enhances reproducibility.

Objectives and Study Overview

This application note demonstrates the use of the Shimadzu UV-1280 UV-VIS spectrophotometer combined with the SINCO Nano Stick microliter cuvette for quantifying DNA at volumes as low as 2–3 µl. The study evaluates linearity, precision and practical usability in measuring calf thymus DNA standards across a wide concentration range.

Methodology

A stock solution of calf thymus DNA (1 mg/ml) was serially diluted in TE buffer (pH 8.0) to yield concentrations from 25 to 1000 ng/µl. For each measurement, 3 µl of sample or TE buffer blank was loaded into the Nano Stick, bubbles and dust were checked visually, and the device was placed in the sample compartment. Baseline correction was performed with TE buffer before sample analysis. Absorbance spectra were recorded in Spectrum mode over 220–350 nm, and DNA quantitation mode at 260 nm was used for precision measurements.

Instrumentation

• Shimadzu UV-1280 UV-VIS Spectrophotometer
• SINCO Nano Stick microliter cuvette (0.5 mm pathlength)

Main Results and Discussion

Absorbance spectra of DNA standards showed a clear peak at 260 nm, a valley at 230 nm and a baseline near 320 nm. The calibration curve was linear between 25 and 1000 ng/µl with a correlation coefficient r2 of 0.9995, demonstrating excellent linearity over a 40-fold virtual dilution range. Ten replicate measurements of a 500 ng/µl sample at 260 nm yielded an average absorbance of 0.451, a standard deviation of 0.006 and an RSD of 1.32 %, indicating high repeatability.

Benefits and Practical Applications

• Minimal sample volume (2–3 µl) conserves valuable material
• Reduced carryover risk due to disposable cuvette design
• High linearity and precision support reliable quantitation
• Simple operation streamlines routine nucleic acid assays

Future Trends and Applications

Advances may include integration with microfluidic platforms for automated sample handling, expansion to protein and metabolite analysis, and portable spectrophotometer systems for field or point-of-care testing. Further miniaturization and high-throughput configurations will support large-scale screening in genomics and diagnostics.

Conclusion

The combination of the Shimadzu UV-1280 spectrophotometer and SINCO Nano Stick provides an efficient, reproducible solution for micro-volume nucleic acid quantitation. Its high linearity, precision and ease of use make it well suited for research and QC laboratories handling limited sample volumes.

References

No external references were cited in the original text.