Chirascan V100 (Brand Name or Equal) Circular Dichroism Instrument

1.0 Requirement Purchase of a Chirascan V100 - Circular Dichroism (CD) Spectrometer – Brand Name or Equal For Structural Analysis of Native and Processed Proteins, Including Peanut and Tree-Nut Allergens 2.0 Background Protein allergenicity is closely linked to secondary and tertiary structure, as well as structural changes caused by processing methods such as roasting, heating, pH shifts, and enzymatic digestion. Circular dichroism spectroscopy is a non-destructive optical technique that provides rapid, sensitive measurements of protein conformation in solution. The agency requires a CD spectrometer capable of generating reproducible, high-resolution spectra for both native and processed proteins to support food-safety, allergenicity, and structural-biology research. The Chirascan V100 is essential in generating reproducible, quantitative data to support allergen-characterization studies and food-safety research. 3.0 Technical Requirements The contractor shall provide a fully integrated circular dichroism (CD) spectrometer system, including software, installation, training, and warranty support. The system will be used to measure, analyze, and compare the structural properties of native and processed healthy proteins and allergenic proteins derived from peanuts and tree nuts. The instrument must deliver high-quality far-UV CD data suitable for evaluating protein secondary structure, conformational stability, and processing-induced structural changes. 4.0 Specifications The CD spectrometer must meet or exceed the following: - Far-UV spectral capability down to at least 180 nm for accurate secondary- structure determination. - High signal-to-noise ratio suitable for dilute protein samples and weakly absorbing allergens. - Low stray light and high optical throughput for reliable far-UV measurements. Ability to measure native, denatured, and processed proteins under identical conditions. - Capability to perform thermal unfolding and refolding studies. - Stable, repeatable measurements for comparative structural analysis. - Have a high-sensitivity solid-state Large-Area Avalanche Photodiode (LAAPD) detector - from 163 to 1150 nm - Allow optics-based, multiwavelength calibration - Dual-Polarising Prism Monochromator - Software controlled lamp and nitrogen-purge for start-up/shutdown scheduling, for example, Active Nitrogen Management System (ANMS) to support fully automated workflows, including unattended operation and integrated cuvette washing - Generate simultaneous, high-precision circular dichroism, absorbance, and fluorescence measurement in a single, automated, thermostatted workflow - Capable of high-sensitivity measurements in far-UV (163 nm to 1,150 nm) spectrum - Have the ability to perform Automated titration/complex mixing and advanced -- 1 of 2 -- thermodynamic studies via Peltier technology - Windows 11 compatible, USB-controlled communication - Total bench area of 2.2 x 0.8 meters (length x depth) and volume of 2.2 x 0.8 x 0.5 meters (length x depth x height) or smaller Sample Handling and Temperature Control The system shall include: A temperature-controlled cuvette holder capable of 0–95°C or better. Compatibility with small-volume cuvettes (≤ 200 μL). Automated or semi-automated data acquisition for reproducibility. Accessories required for routine protein structural analysis. Software Requirements The software shall: Provide automated secondary-structure estimation (α-helix, β-sheet, random coil). Support spectral overlay, subtraction, and comparison for native vs. processed proteins. Export data in standard formats (e.g., CSV, TXT, XML) for research and documentation. Include secure data handling consistent with federal research requirements. Installation and Training The contractor shall: Deliver and install the CD spectrometer at the designated government facility. Perform full system calibration and verification. Provide on-site training for instrument operation, maintenance, and data analysis. Supply all necessary documentation, including user manuals and maintenance guides. Warranty and Support The contractor shall provide: A minimum five-year warranty covering parts, labor, and on-site service. Technical support for troubleshooting, method development, and software updates. Place of Delivery: USDA, ARS, Southern Regional Research Center 1100 Allen Toussaint Blvd. New Orleans, LA 70124 Delivery: 60 days ARO -- 2 of 2 --