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Direct Detect® Spectrometer Protocols

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How the Direct Detect® Spectrometer Works: A Step-By-Step Protocol

1. Sample Loading

Sample Loading
  • Apply 2 µL of sample solution (position 2-4) and sample buffer blank (position 1) on the card.

2. Measure (2 min / card)

FTIR Spectrometer measurement protocol
  • Insert the card vertically into the slot in the top of the sampling accessory.
  • The card notch should face towards the center of the instrument (align arrows on card and instrument).
  • Instrument dries samples, then measures each spot.
  • Acquire spectra.

3. FTIR Analysis (Quantify Protein Samples)

FTIR Analysis (quantify protein samples)
  • Statistical data displayed for all 3 samples.
  • User can select which data points to exclude, if any.
  • User has option to print a report of current data, or export as a .CSV file.
  • Compare results to internal Amino Acid Analysis verified BSA standard or create your own standard curve.
  • Assay-free analysis means you can save your standard curves.

Direct Detect® Fourier transforms FTIR Spectrometer resultsSystem Components

  • Direct Detect® FTIR Spectrometer
    • Compact footprint spectrometer (11 in x 8 in; 30 cm x 22 cm)
    • Dell Latitude® 2120 Netbook & Power Adapter
    • Netbook Stand
    • Ethernet Cable
    • Spotting tray
    • 1 pack Assay-free Cards
  • Assay-Free Card
    • Preserves precious samples—requires only 2 ìL per analysis
    • Dynamic range: 0.2 mg/mL – 5 mg/mL
    • Analyzes and quantifies any protein or peptide as small as 3 amino acids
    • Hydrophilic PTFE membrane transparent in most IR spectra
    • Broad chemical compatibility
  • Software
    • Enables numerical and FTIR spectral analysis
    • After calibration upon installation, further standard curves not required.

Guide to Choosing the Right Protein/Peptide Analysis Method for Direct Detect® Quantitation

It’s easy to obtain accurate protein quantitation when you use the right standard curve and spectral analysis appropriate for your IR signals of your analyte and your particular baseline. This technical note explains the three methods and how to decide which one to use for best results.
Note: User guides can be accessed from the Help menu of the software.