Table 3 Relative efficiencies of methods of gluten analysis for situations where cultivar identification is required
Subject | SDS-PAGE | 2-DE | MALDI-TOF-MS | PCR |
|---|---|---|---|---|
Required sample amount | 40 μg (Protein) | 150 μg (Protein) | 0.04 μg (Protein) | 2 μL (DNA) |
Purity required | Low | High | High | Medium |
Number of alleles | 19 | 22 | 21 | 16 |
Alleles efficiently resolved | Glu-B3b and Glu-B3g, Glu-B3d and Glu-B3i, | Glu-A3e, Glu-A3f, Glu-A3g, Glu-B3b, Glu-B3g, Glu-B3ab, Glu-B3ac, Glu-B3ad, Glu-D3l and Glu-D3m | Glu-A3e, and Glu-A3f; Glu-D3a, Glu-D3b, Glu-D3c, and Glu-D3m | Glu-A3e and Glu-A3f, Glu-B3d and Glu-B3i, Glu-B3f and Glu-B3g |
Mass accuracy | Inaccurate | Inaccurate | Accurate | Accurate |
pI | Unknown | Known | Unknown | Unknown |
Cost of equipment | ≈$7,000 | ≈$30,000 | ≈$20,000-400,000 | ≈$5,500 |
Cost per sample | ≈$1.0 | ≈$70.0 | ≈$0.3 | ≈$0.3 |
Number of samples analysed per day for skilled technician | 30-160* | 1 | 100 | 100 |
Automation | Not possible | Not possible | Possible | Possible |
Experience required | Considerable | Considerable | Less | Less |
Safety | High toxicity | High toxicity | Safe | Toxicity |
False positives | No | Yes | No | Yes |
Accuracy level | ++ | +++ | ++ | ++ |