. Author manuscript; available in PMC: 2010 Dec 1.

Published in final edited form as: J Proteome Res. 2009 Dec;8(12):5523–5531. doi: 10.1021/pr900603n

Table 3.

Summary of serum phosphopeptide identification by LTQ-ETD ^a

	Total matched spectra	Total non- phosphopeptide spectra (% total)	Total phosphopeptide spectra (% total)	Total unique phosphopeptides
One round TiO₂ enrichment	46	25 (54.3%)	21 (45.7%)	15
Two rounds TiO₂ enrichment	50	9 (18.0%)	41 (82.0%)	13
Albumin/IgG depletion fraction	33	11 (33.3%)	22 (66.7%)	13
Albumin/IgG bound fraction	12	6 (50.0%)	6 (50.0 %)	4

All results were obtained using the following criteria to filter the EQUEST search results: “ranked top #1; Probability (EQUEST) > 7”.