Micro Volume Photometric Measurement of Nucleic Acid using TrayCell with UV-1280

Importance of the Topic

Accurate quantification of nucleic acids in microvolumes is essential for molecular biology, diagnostics, and research where sample availability is limited. Traditional cuvettes require larger volumes and risk contamination, making ultra-micro volume approaches highly valuable.

Objectives and Study Overview

This application note demonstrates microvolume photometric measurement of nucleic acids using the Shimadzu UV-1280 spectrophotometer equipped with Hellma TrayCell. The goal is to assess measurement repeatability and purity analysis of a 100 bp DNA ladder.

Methodology

Samples of a Promega 100 bp DNA ladder (3 µl) were pipetted onto the TrayCell window. Baseline correction was performed using a reference blank. Measurements were conducted at 260 nm and 280 nm in DNA quantitation mode to determine concentration and purity.

Instrumentation Used

• Shimadzu UV-1280 UV-VIS spectrophotometer with six bio method mode protocols (DNA Quantitation, Lowry, BCA, CCB, Biuret, UV).
• Hellma TrayCell ultra-micro cell with 1 mm and 0.2 mm path length caps, enabling sample volumes of 0.7–10 µl and virtual dilution factors of 1:10 and 1:50.

Main Results and Discussion

Ten replicate measurements of the DNA ladder at 260 nm yielded an average absorbance of 0.275, a standard deviation of 0.004, and an RSD of 1.32%. Purity ratios (A260/A280 and A260/A230) were within expected ranges (1.8–1.9 and >2.0 respectively), confirming minimal contamination.

Benefits and Practical Applications

• High reproducibility with minimal sample volume and reduced dilution errors.
• Rapid analysis suitable for routine quality control in genomics, proteomics, and clinical laboratories.
• Cost and time savings by eliminating extensive cleaning steps and sample preparation.

Future Trends and Potential Applications

Advancements may include integration with automation platforms, expanded wavelength ranges for RNA and protein profiling, and coupling with microfluidic systems for high-throughput analysis.

Conclusion

The combination of Shimadzu UV-1280 bio method mode and Hellma TrayCell enables reliable microvolume nucleic acid measurements with excellent precision and purity assessment.

References

Shimadzu (Asia Pacific) Pte. Ltd. (2015). Application Note AD-0088: Micro Volume Photometric Measurement of Nucleic Acid using TrayCell with UV-1280.