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Supplier Showcase Seminar: QC & Enzymatic Analyses Thursday, June 19 1:30 pm - 3:00 pm Chair: Patricia Howe, Patricia Howe Wines, California Theme: Improve and understand your Malic and Glu/Fru analysis Speakers: Jason Gerard, Tom Eddy Wines, California Patricia Howe, Patricia Howe Wines, California Samantha Kollar, Vinquiry, California Michael Moyer, Walla Walla Community College, Washington Geoffrey Anderson, Unitech Scientific, California
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ASEV Supplier s Showcase, Portland OR June 19, 2008 Improve and understand your Malic & Glu/Fru analyses Issues in Automated Analyses Geoffrey Anderson Unitech Scientific LLC Lakewood, CA Visit us: www.unitechscientific.com www.unitechscientific.com
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Advantages of Automation Efficiency: more data... Faster Better Accuracy & Reliability Multi-point Standard Curves (improved accuracy over analytical range) Verified Calibrations (Check Wines as controls, Levy Jennings Charts) Verified Calibrations (Check Wines as controls, Levy Jennings Charts) Systematic (fewer random errors)
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More More Advantages of Automation Easier Random Access - Random Access - multiple tests run together Easy assay set-up Easy assay set-up Easy accurate reporting Easy accurate reporting Curve Editing Curve Editing Store Calibration Curves Store Calibration Curves
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Managing the Issues Troubleshooting – Common Themes Reagent Issues Spectrophotometers vs. Analyzers Discrete & Other Analyzers
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Analyzer Components & Functions Operating software2 syringe pumps wash head wash head Optical system samplesreagentsReactions DI water
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Controlling Potential Sources of Error Reagents, Standards Fluid Handling, Pipetting Photometric Analysis & Samples & cleanliness
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ISSUE: Poor splits Case Study #1(a) many samples affected, results were good in the morning run RESOLUTION: check for air bubbles check for reagent spills (photometry issues)
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ISSUE: Poor splits (extreme samples) Case Study #1(b) only dry wines (or only juice samples) affected RESOLUTION: check delta ABS (raw data) high Std ABS) consider alternate protocols
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2 Protocols: Accuracy over a Broad Analytical Range Sample Volumes 1) L-Malic dry (for high sensitivity, 0.02 – 0.5 G/L) 2uL Sample volume 2) L-Malic juice (detecting high levels, 0.2 – 5.0 G/L) 2uL Sample Volume pre-diluted 10-fold
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Problem Solving Approach: Isolate instrument issues Instrument Diagnostics (example) a)Self Test Measure Precision & Accuracy (Pipette delivery of dye + diluent to cuvettes) b)Blank (measure d.i. water in cuvette) c)Photometer Voltage(s) (i.e. response to light at each wavelength)
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Distinguish instrument vs. chemistry issues Self Test (example) Sunday, June 08, 2008, 11:01 Lamps - OK Blank - OK Small Sample Medium Sample Large Sample Pipetting Accuracy: OK OK OK Photometer/Plate Positioning: OK OK OK PASSED (Blank out of recommended range) DETAILS: (6.3.1.162/1720/0.95/0.92) Temperature at start: 29.3 °C Temperature at end: 24.8 °C Blank Abs: 0.0016
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Distinguish instrument vs. chemistry issues Self Test (precision detail) Type Target Mean SD %CV %Diff ------------------------------------------------------------------ Large 2.4190 2.4918 0.0147 0.5898 3.0091 Medium 1.3440 1.4202 0.0082 0.5756 5.6687 Small 0.2690 0.3071 0.0034 1.0930 14.1654
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ISSUE: Standard Curve Case Study #2(a) LMA curve is OK, G/F curve has poor duplicates & poor r 2 value RESOLUTION: Verify delta A values (replace G/F reagents) Consider editing G/F Standard Curve Run Self Test
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Editing a Standard Curve 5-Point Calibration Curve r 2 = 0.95972
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Editing: Select Calibration Points
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Editing a Standard Curve 4-Point Calibration Curve r 2 = 0.99997
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ISSUE: Standard Curve Case Study #2(b) Curve falls-off at top end Likely Reagent Cause: Substrate depletion (Working Reagent) or weak enzyme activity RESOLUTION: Replace G/F Reagents
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Potential ISSUE: Reagent Stability (Reagents may be left on-board) RESOLUTION: Anticipate Deterioration & Dilution - Schedule - Fresh Working Reagents - Use Enzyme ALIQUOTS & Standards ALIQUOTS - Control Temperature as required
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ISSUE: Standard Curve Case Study #2(c) Everything was great Friday, nothing looks good Monday Verify change in system RESOLUTION : Weekly P.M. (e.g. Self Test, check tubing, etc.) Check for air bubbles, clean supply water, clean cuvettes, etc.
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ISSUE : Check-wine is Out of Range Case Study #3D-Fru is low, D-Glu is OK Note: D-Fru reaction may not be complete (PGI Reaction is the rate-limiting step) RESOLUTION: Load fresh PGI aliquot
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ISSUE: Self Test: Filter Voltage fails Photometer P.M. RESOLUTION: Photometer P.M. Check & clean lamp(s) Check & clean lamp(s) Clean Photometer(s) lense(s) Clean Photometer(s) lense(s) Clean any reagent spills Clean any reagent spills Check cuvettes for cleanliness & scratches Check cuvettes for cleanliness & scratches
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Optical Design 4 optical channels align with 4 microwells and read each well at all 8 wavelengths (340-750nm)
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Quality Control Tracking LIS compatible
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Preventive Maintenance for Accurate Automated Results A. Fluid Handling System (e.g. bubbles) B. Photometry System (lamp voltage, spills etc.) C. System Diagnostics (self test) D.Daily/Weekly (prime, bleach or change tubing, water supply, confirm performance)
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Data Issues Sample Data base (avoid transcription errors) Review results on-screen (Accept or Rerun) Sorting Data, Print & Distribute Reports & export reports (avoid transcription errors)
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Issues in Automated Analyses Geoffrey Anderson Unitech Scientific LLC Lakewood, CA Visit us: www.unitechscientific.com www.unitechscientific.com
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