TABLE 2.
Reproducibility in the quantification of ammonium ion adducts of PtdInsPs
| Observed (n = 3) | ||||||||
| Concentration (pmol/ml) | 18:0/20:4 PtdIns + 1Met | 18:1/18:1 PtdInsP + 3Met | 18:0/20:4 PtdInsP2 + 5Met | 18:0/20:4 PtdInsP3 + 7Met | ||||
| Expected | Mean | (RSD) | Mean | (RSD) | Mean | (RSD) | Mean | (RSD) |
| 10 | 10 | (23) | 10 | (5) | 12 | (25) | 12 | (17) |
| 100 | 128 | (13) | 120 | (12) | 109 | (10) | 112 | (16) |
| 1,000 | 1,095 | (9) | 1,090 | (8) | 1,160 | (5) | 1,127 | (11) |
Neutral loss scans were performed, and peak areas for specific PtdInsPs were used to evaluate the reproducibility of ammonium ion adduct formation. The peak area of each PtdInsPs species was normalized to that of the corresponding internal standard. RSD indicates the relative standard deviation of three experiments.