TABLE 1.
Comparison of the numbers of metabolites at multiple detectability levels across different collection methodsa
| Detectability level of metabolites (%) |
Method | No. of known metabolites |
No. of known metabolites shared by GS and method (% of GS) |
No. of known metabolites shared by GS and method on day 0 |
No. of known metabolites shared by GS and method on day 4 |
|---|---|---|---|---|---|
| All metabolites | Immediate freezing | 1,986 | |||
| 95% ethanol | 1,992 | 1,983 (99.8) | 1,977 | 1,980 | |
| RNAlater | 1,986 | 1,977 (99.5) | 1,970 | 1,964 | |
| Microlution | 1,986 | 1,979 (99.6) | 1,975 | 1,970 | |
| OMNIgene Gut | 1,929 | 1,921 (96.7) | 1,892 | 1,913 | |
| ≥50 | Immediate freezing | 1,952 | |||
| 95% ethanol | 1,948 | 1,941 (99.4) | 1,933 | 1,932 | |
| RNAlater | 1,883 | 1,879 (96.3) | 1,889 | 1,858 | |
| Microlution | 1,913 | 1,905 (97.6) | 1,912 | 1,895 | |
| OMNIgene Gut | 1,787 | 1,768 (90.6) | 1,772 | 1,776 | |
| ≥80 | Immediate freezing | 1,867 | |||
| 95% ethanol | 1,878 | 1,848 (99.0)b | 1,849 | 1,847 | |
| RNAlater | 1,752 | 1,729 (92.6)b | 1,685 | 1,691 | |
| Microlution | 1,847 | 1,811 (97.0)b | 1,796 | 1,793 | |
| OMNIgene Gut | 1,680 | 1,624 (87.0)b | 1,617 | 1,612 | |
| 100 | Immediate freezing | 1,772 | |||
| 95% ethanol | 1,745 | 1,698 (95.8) | 1,734 | 1,727 | |
| RNAlater | 1,230 | 1,206 (68.1) | 1,456 | 1,299 | |
| Microlution | 1,659 | 1,602 (90.4) | 1,643 | 1,656 | |
| OMNIgene Gut | 1,469 | 1,398 (78.9) | 1,452 | 1,479 | |
a
GS, gold standard.
b
The subset of known metabolites shared by the GS and other collection methods for comparison analysis of stability, concordance, and reliability at the ≥80% detectability level.