Presentation is loading. Please wait.

Presentation is loading. Please wait.

Commercial Gluten Test Kits / Methods Jupiter Yeung, PhD Principal Scientist Food Products Association FDA Gluten Free Meeting, Aug 19, 2005 Jupiter Yeung,

Similar presentations


Presentation on theme: "Commercial Gluten Test Kits / Methods Jupiter Yeung, PhD Principal Scientist Food Products Association FDA Gluten Free Meeting, Aug 19, 2005 Jupiter Yeung,"— Presentation transcript:

1 Commercial Gluten Test Kits / Methods Jupiter Yeung, PhD Principal Scientist Food Products Association FDA Gluten Free Meeting, Aug 19, 2005 Jupiter Yeung, PhD Principal Scientist Food Products Association FDA Gluten Free Meeting, Aug 19, 2005

2 Gliadin Detection Methods Immunochemical ELISA Lateral Flow Device Immunoblotting PCR MS MALDI-TOF LC/MS/MS Immunochemical ELISA Lateral Flow Device Immunoblotting PCR MS MALDI-TOF LC/MS/MS

3 22 Capture Antibody Detector Antibody Signal Sandwich ELISA

4 Skerritt mAb –  -gliadin (  -gliadin) – wheat – 100% rye – 120% barley – 5% Mendez R5 mAb – QXPFP toxic epitopes of , , ,  -gliadins – Equally to wheat, rye and barley Both Ab recognize raw and cooked prolamins Skerritt mAb –  -gliadin (  -gliadin) – wheat – 100% rye – 120% barley – 5% Mendez R5 mAb – QXPFP toxic epitopes of , , ,  -gliadins – Equally to wheat, rye and barley Both Ab recognize raw and cooked prolamins Gliadin Antibodies Specificity

5 CompanyProductLOD*LOQ*Range*ReplicatesCosts NeogenAlert (Qualitative)101$237/20Sampl Veratox $465/38Sampl R-BiopharmRidaScreen $425/96 wells RidaScreen Fast $400/48 wells TepnelGluten Assay Kit, AOAC or High sensitivity $425/96 wells HallmarkHAVen Gluten, AOAC or High sensitivity $425/96 wells DiffchambTransia Plate Gluten $500/96 wells Transia Plate Prolamins $500/96 wells MorinagaWheat Protein0.3* $600/96 wells Commercial Gliadin ELISA Kits * ppm gliadin ppm gluten = ppm gliadin x 2 * ppm gliadin ppm gluten = ppm gliadin x 2 Converted to ppm from  g/mL

6 CompanyProductValidation NeogenAlert Veratox R-BiopharmRidaScreen RidaScreen FastPWG ring trial TepnelBioKit Gluten(AOAC OM) High Sensitivity HallmarkHAVen Gluten(AOAC OM) High Sensitivity DiffchambTransia Plate GlutenNFA, Sweden Transia Plate Prolamins MorinagaWheat ProteinNIHS, Japan Commercial Gliadin ELISA Kits

7 ppm gliadin controls Gliadin ELISA

8 CompanyProductLOD (ppm gluten) Costs R-BiopharmRida Quick10 $200 / 20 strips TepnelGluten Rapid100$150 / 10 strips Gluten Home100$ 75 / 5 strips Lateral Flow Device (Dipstick) Lateral Flow Device (Dipstick) Positive can mean less than LOD

9 Lateral Flow Device

10 Lateral Flow Device

11

12 Issues with Gluten Test Kits Ab has different specificities to different prolamins, e.g. Skerritt Ab Various results from different extraction media: 40-60% EtOH, cocktails Different standards used from different kits False positives and negatives require a confirmatory test Limited availability of confirmatory test to most food lab No sampling plan Ab has different specificities to different prolamins, e.g. Skerritt Ab Various results from different extraction media: 40-60% EtOH, cocktails Different standards used from different kits False positives and negatives require a confirmatory test Limited availability of confirmatory test to most food lab No sampling plan

13 Extraction Media Aq. Alcohol (40-60% EtOH) Cocktail (reducing agent + others) - interaction of Ab and Ag Aq. Alcohol (40-60% EtOH) Cocktail (reducing agent + others) - interaction of Ab and Ag

14 Matrix Effect Cocktail (reducing agent + others) - interference with complex food matrices, e.g. milk - interaction of Ab and Ag Samples with high polyphenols, tannins and syrups require fish gelatin to improve recovery Cocktail (reducing agent + others) - interference with complex food matrices, e.g. milk - interaction of Ab and Ag Samples with high polyphenols, tannins and syrups require fish gelatin to improve recovery

15 Hasselberg et al. Proceeding of the 18 th Meeting, WPGAT, 2004 Hasselberg et al. Proceeding of the 18 th Meeting, WPGAT, 2004 Effects of Extraction Media

16 Effect of Partial Hydrolysis Ferre et al. Proceeding of the 18 th Meeting, WPGAT, 2004 Ferre et al. Proceeding of the 18 th Meeting, WPGAT, 2004

17 Reference Materials IRMM-480 Wheat Gliadin NIST SRM 1567a Wheat Flour RM 8418 Wheat Gluten RM 8436, 8437, 8438, 8441a Others IRMM-480 Wheat Gliadin NIST SRM 1567a Wheat Flour RM 8418 Wheat Gluten RM 8436, 8437, 8438, 8441a Others

18 Confirmation Methods Ab-Western blot PCR – qualitative, quantitative MS – MALDI-TOF, LC/MS/MS Ab-Western blot PCR – qualitative, quantitative MS – MALDI-TOF, LC/MS/MS

19 Garcia et al., Proceeding of the 18 th Meeting, WPGAT, 2004

20 Detection & Speciation Wheat Gliadins Rye Scalins Barley Hordeins Oat Avenins Ab-based+- PCR++++ MS++++


Download ppt "Commercial Gluten Test Kits / Methods Jupiter Yeung, PhD Principal Scientist Food Products Association FDA Gluten Free Meeting, Aug 19, 2005 Jupiter Yeung,"

Similar presentations


Ads by Google