Table 1

The expected pH ranges per fraction were calculated according to the IPG strip supplier data and the OFFGEL well dimensions and compared with experimental pI obtained for plasma and secretome samples.



Plasma
 Secretome
Fraction
 Expected pH range
 Peptide pI Average
 s.d.
 Peptide pI Average
 s.d
1
 3.35
 3.61
 4.11
 0.40
 4.24
 0.92
2
 3.61
 3.88
 4.17
 0.56
 4.11
 0.31
3
 3.88
 4.14
 4.29
 0.22
 4.24
 0.26
4
 4.14
 4.40
 4.53
 0.32
 4.40
 0.19
5
 4.40
 4.66
 4.67
 0.42
 4.56
 0.33
6
 4.66
 4.93
 4.77
 0.45
 4.90
 0.84
7
 4.93
 5.19
 5.25
 0.59
 5.55
 0.54
8
 5.19
 5.45
 5.61
 0.36
 5.33
 0.65
9
 5.45
 5.71
 5.61
 0.39
 5.50
 0.41
10
 5.71
 5.98
 5.71
 0.67
 5.66
 0.39
11
 5.98
 6.24
 5.81
 0.70
 5.88
 0.36
12
 6.24
 6.50
 5.99
 0.70
 5.88
 0.42
13
 6.50
 6.76
 6.10
 0.75
 6.11
 0.61
14
 6.76
 7.03
 6.20
 0.85
 6.22
 0.72
15
 7.03
 7.29
 6.48
 0.80
 6.78
 1.24
16
 7.29
 7.55
 6.63
 0.78
 6.73
 0.87
17
 7.55
 7.81
 6.89
 0.87
 6.79
 0.88
18
 7.81
 8.08
 7.75
 1.13
 6.88
 0.95
19
 8.08
 8.34
 8.20
 1.26
 7.64
 1.81
20
 8.34
 8.60
 8.36
 1.03
 7.78
 1.70
21
 8.60
 8.86
 8.33
 1.05
 8.33
 1.20
22
 8.86
 9.13
 8.31
 1.23
 8.42
 0.97
23
 9.13
 9.39
 8.49
 1.06
 8.77
 1.04
24
 9.39
 9.65
 8.48
 1.42
 9.22
 1.13

(s.d. = standard deviation)

Chenau et al. Proteome Science 2008 6:9   doi:10.1186/1477-5956-6-9