Zuofei zNano-3 Ultra-Micro Spectrophotometer

Overview

The Zuofei zNano-3 Ultra-Micro Spectrophotometer is an engineered solution for rapid, reagent-free quantification and spectral characterization of nucleic acids, proteins, and microbial cultures. Based on fixed-pathlength microvolume UV-Vis absorbance spectroscopy—leveraging a high-stability xenon flash lamp and precision quartz-fiber optical path—it delivers accurate concentration and purity assessment from just 0.5–2 µL of undiluted sample. Unlike conventional cuvette-based instruments requiring dilution and calibration, the zNano-3 employs an auto-adjusting optical path mechanism that dynamically compensates for sample absorbance, enabling direct measurement of highly concentrated biomolecules (up to 200× the upper limit of standard 10-mm cuvettes). Its continuous 190–850 nm spectral acquisition supports not only A₂₆₀/A₂₈₀ and A₂₆₀/A₂₃₀ ratio analysis for nucleic acid integrity but also protein quantification at 280 nm, OD₆₀₀ monitoring for microbial growth kinetics, and baseline-corrected spectral deconvolution across the far-UV to near-IR range.

Key Features

• Integrated 7-inch capacitive touchscreen interface—fully standalone operation with no PC dependency
• Microvolume mode (0.5–2 µL) with automatic pathlength adjustment; eliminates manual dilution and associated pipetting error
• Dual-mode optical design: microvolume drop-on-base + standard 10-mm cuvette compatibility for flexible workflow integration
• Xenon flash lamp source (rated lifetime >10⁹ flashes) with zero warm-up time and intelligent on-demand activation—reducing thermal drift and extending component longevity
• Optical resolution: 2 nm spectral bandwidth; wavelength accuracy ±0.003 Abs (traceable to NIST-calibrated standards)
• Built-in thermal printer for GLP-compliant hardcopy reporting with timestamp, sample ID, and full spectral overlay
• Low power consumption: <15 W operational / 5 W standby; universal AC input (100–240 V), DC 24 V/2 A option available

Sample Compatibility & Compliance

The zNano-3 accommodates diverse biological and biochemical samples without modification or consumables: double-stranded DNA (2–15,000 ng/µL), RNA, purified proteins, oligonucleotides, viral particles, and bacterial/yeast suspensions. Its OD₆₀₀ measurement capability (range: 0–4.000 Abs, accuracy ±0.005 A below 2.0 Abs) meets standard requirements for microbial culture density tracking per ISO 8199 and ASTM E2554 protocols. While not certified under FDA 21 CFR Part 11, the instrument supports audit-ready data handling through timestamped internal storage (USB export), immutable print logs, and user-defined sample naming—facilitating alignment with GLP and GMP documentation practices in academic, QC, and contract research environments.

Software & Data Management

All spectral acquisition, calculation, and reporting are executed onboard via embedded firmware. No external software installation is required. Raw absorbance spectra (1 nm intervals), derived parameters (A₂₆₀, A₂₈₀, A₂₃₀, ratios, extinction coefficients), and OD₆₀₀ curves are stored in CSV format on removable USB drives. The system retains up to 1,000 recent measurements with metadata (date/time, operator ID if enabled, wavelength settings). Exported files are compatible with common analysis platforms including GraphPad Prism, R, and Python pandas for secondary statistical modeling or LIMS integration. Firmware updates are delivered via USB—no network connectivity required, preserving lab cybersecurity posture.

Applications

• Nucleic acid quantification and purity screening (A₂₆₀/A₂₈₀ ≥1.8 for DNA; ≥2.0 for RNA; A₂₆₀/A₂₃₀ >2.0 indicates low organic/inorganic contamination)
• Protein concentration determination using A₂₈₀ with optional extinction coefficient input (e.g., IgG = 1.4 mL·mg⁻¹·cm⁻¹)
• Real-time OD₆₀₀ monitoring of E. coli, S. cerevisiae, and other suspension cultures during fermentation or induction studies
• Verification of PCR/qPCR template integrity prior to amplification
• Quality control of synthetic oligos, CRISPR gRNAs, and modified nucleotides
• Field-deployable nucleic acid verification in biosafety level-2 mobile labs or core facility satellite stations

FAQ

Does the zNano-3 require routine calibration with standard reference materials?
No—factory calibration is stable over the instrument’s operational lifetime. Users may perform optional verification using NIST-traceable neutral density filters or dsDNA standards (e.g., Lambda DNA at 50 ng/µL), but recalibration is not necessary under normal use.
Can the zNano-3 measure fluorescent dyes or labeled biomolecules?
The zNano-3 is an absorbance-only platform. It does not include excitation/emission optics or fluorescence detection capability. For fluorescence applications, refer to the zNano-4AF model.
Is the cuvette holder compatible with standard 10-mm quartz or plastic cuvettes?
Yes—the integrated cuvette mode accepts industry-standard 10-mm pathlength cells (12.5 × 12.5 mm footprint) with auto-zeroing against air or blank solvent.
What is the minimum detectable dsDNA concentration in microvolume mode?
0.04 A (equivalent to ~2 ng/µL dsDNA at 10-mm pathlength); detection limit confirmed per ISO 17025 validation guidelines using serial dilutions of certified reference material.
How is data security and user accountability managed?
The device supports operator login (optional password protection), timestamps all measurements, and stores raw spectra with uneditable metadata—enabling traceability for internal QA reviews and external audits.