Table 2.
Comparison of DNA yield, purity and real-time PCR results for a positive control plant gene in maize-containing foodstuffs and feeds extracted with different methods
| Extraction method | DNA yield (ng/μL) | DNA purity (A260/A280) | Real-time (+/total) | Ct | |
|---|---|---|---|---|---|
| Flour | Foodproof | 50.17 ± 5.8c | 1.92 ± 0.1c | 6/6 | 18.77 ± 0.88b |
| GeneSpin | 163.46 ± 8.9b | 1.99 ± 0.1b | 6/6 | 18.73 ± 0.51b | |
| Wizard | 304.4 ± 21.8a | 1.85 ± 0.1d | 6/6 | 19.11 ± 0.71b | |
| DNeasy | 15.13 ± 2.3d | 2.10 ± 0.1a | 6/6 | 20.75 ± 0.77a | |
| CTAB | 170.0 ± 7.9b | 1.73 ± 0.1e | 6/6 | 21.11 ± 0.95a | |
| Starch | Foodproof | 8.6 ± 1.0b | 1.16 ± 0.2d | 6/6 | 21.20 ± 0.82d |
| GeneSpin | 10.3 ± 2.1b | 1.59 ± 0.1ab | 6/6 | 26.53 ± 0.55a | |
| Wizard | 76.0 ± 3.6a | 1.60 ± 0.1a | 6/6 | 25.55 ± 0.44c | |
| DNeasy | 1.9 ± 0.4d | 1.58 ± 0.1ab | 6/6 | 24.82 ± 1.10b | |
| CTAB | 38.0 ± 0.6c | 1.51 ± 0.1b | 6/6 | 23.89 ± 0.88c | |
| Bread | Foodproof | 40.87 ± 5.11c | 1.42 ± 0.2c | 6/6 | 21.58 ± 0.83c |
| GeneSpin | 36.33 ± 4.5d | 2.04 ± 0.1a | 6/6 | 21.31 ± 0.48c | |
| Wizard | 85.50 ± 5.7b | 1.48 ± 0.1c | 6/6 | 23.71 ± 0.73a | |
| DNeasy | 7.29 ± 0.8e | 1.48 ± 0.1c | 6/6 | 21.35 ± 0.77c | |
| CTAB | 129.44 ± 2.8a | 1.57 ± 0.1b | 6/6 | 23.16 ± 0.26b | |
| Flakes | Foodproof | 67.23 ± 2.1b | 1.83 ± 0.1b | 6/6 | 20.15 ± 0.75e |
| GeneSpin | 27.25 ± 2.4d | 1.87 ± 0.1b | 6/6 | 21.78 ± 0.32d | |
| Wizard | 70.0 ± 0.63a | 1.68 ± 0.1c | 6/6 | 22.44 ± 0.65c | |
| DNeasy | 4.68 ± 0.2 e | 1.99 0.1a | 6/6 | 23.51 ± 0.54b | |
| CTAB | 55.92 ± 3.8c | 1.67 ± 0.1c | 6/6 | 24.65 ± 0.65a | |
| Chips | Foodproof | 55.82 ± 3.3b | 1.73 ± 0.1b | 6/6 | 20.47 ± 0.43e |
| GeneSpin | 50.81 ± 3.6c | 2.03 ± 0.1a | 6/6 | 20.10 ± 0.61d | |
| Wizard | 71.93 ± 5.9a | 1.75 ± 0.1b | 6/6 | 22.80 ± 0.51b | |
| DNeasy | 17.93 ± 2.6c | 1.70 ± 0.1b | 6/6 | 23.57 ± 0.61 a | |
| CTAB | 69.74 ± 2.3a | 1.68 ± 0.1b | 6/6 | 21.16 ± 0.43 c | |
| Maize-based biscuit | Foodproof | 30.0 ± 2.6d | 1.28 ± 0.1b | 6/6 | 23.64 ± 0.97d |
| GeneSpin | 60.84 ± 7.3b | 1.37 ± 0.1a | 6/6 | 24.67 ± 0.63c | |
| Wizard | 44.1 ± 6.5 c | 1.38 ± 0.1a | 6/6 | 25.95 ± 0.59b | |
| DNeasy | 25.90 ± 3.9e | 125 ± 0.1b | 6/6 | 25.92 ± 0.51b | |
| CTAB | 111.6 ± 4.7a | 1.26 ± 0.1b | 6/6 | 29.75 ± 0.37a | |
| Diet breakfast cereal | Foodproof | 71.35 ± 8.8d | 1.52 ± 0.1b | 6/6 | 21.46 ± 0.97c |
| GeneSpin | 117.63 ± 9.8c | 1.76 ± 0.1a | 6/6 | 20.34 ± 0.54d | |
| Wizard | 273.7 ± 18.0b | 1.52 ± 0.1b | 6/6 | 23.90 ± 0.62a | |
| DNeasy | 14.63 ± 4.4e | 1.56 ± 0.1b | 6/6 | 22.15 ± 0.83b | |
| CTAB | 999.9 ± 93.7a | 175 ± 0.1a | 6/6 | 20.71 ± 0.71d | |
| Canned-maize | Foodproof | 89.85 ± 7.7c | 1.58 ± 0.1c | 6/6 | 21.46 ± 0.63 cd |
| GeneSpin | 29.43 ± 3.9d | 1.71 ± 0.1b | 6/6 | 21.75 ± 0.53c | |
| Wizard | 103.7 ± 10.5b | 2.10 ± 0.1a | 6/6 | 24.49 ± 0.67a | |
| DNeasy | 19.50 ± 2.5 e | 2.15 ± 0.1a | 6/6 | 23.24 ± 0.77b | |
| CTAB | 203.37 ± 10.1a | 1.63 ± 0.1c | 6/6 | 20.97 ± 0.80d | |
| Feed | Foodproof | 36.98 ± 6.3d | 1.93 ± 0.1a | 6/6 | 22.19 ± 0.56c |
| GeneSpin | 63.99 ± 6.1c | 1.96 ± 0.1a | 6/6 | 21.02 ± 0.55d | |
| Wizard | 103.7 ± 10.5b | 1.67 ± 0.1c | 6/6 | 22.87 ± 0.61b | |
| DNeasy | 48.2 ± 3.6d | 1.79 ± 0.1b | 6/6 | 25.23 ± 1.18a | |
| CTAB | 890.2 ± 40.9a | 1.53 ± 0.1d | 6/6 | 20.53 ± 0.10d | |
| Seed | Foodproof | 283.71 ± 38.8c | 1.91 ± 0.1a | 6/6 | 20.55 ± 0.65c |
| GeneSpin | 403.95 ± 60.2b | 1.93 ± 0.1a | 6/6 | 18.21 ± 0.92 b | |
| Wizard | 73.3 ± 17.2d | 1.81 ± 0.1b | 6/6 | 21.10 ± 062 a | |
| DNeasy | 65.47 ± 13.8d | 1.82 ± 0.1b | 6/6 | 21.75 ± 0.36 b | |
| CTAB | 532.4 ± 63.2 | 1.75 ± 0.1c | 6/6 | 19.75 ± 0.54 b | |
| CRMs | Foodproof | 18.37 ± 81.6b | 1.80 ± 01a | 6/6 | 16.10 ± 0.41b |
| GeneSpin | 373.54 ± 47.7a | 1.77 ± 0.1a | 6/6 | 15.48 ± 0.33c | |
| Wizard | 49.77 ± 26.7ab | 1.78 ± 0.1a | 6/6 | 15.65 ± 0.46d | |
| DNeasy | 263.0 ± 46.1c | 1.66 ± 0.1b | 6/6 | 18.17 ± 0.57b | |
| CTAB | 46.37 ± 51.0c | 1.64 ± 0.1b | 6/6 | 18.10 ± 0.39d |
*Values represented as average ± standard deviation for six replicates