The cases were treated as independent, however, in the analyses described next, because treating the data as a complex sample composed of clustered observations would have complicated the analyses greatly, and because the exact probability values automatically generated by these particular analyses were not really important.
If 0.4 nl of a complex sample, containing 1 g/l of a 180 kDa protein such as C3 (corresponding to 2.2 µM), is transferred to a slide, it will contain approximately 1.3×109 molecules of this particular protein.
Nonetheless, in a single GC/MS analysis of a complex sample, often only ∼100 of the 200 500 observed mass spectral features can routinely be identified; the rest remain unknown, along with their potential importance to the research question being studied.
To analyze a complex sample in terms of its protein contents it is often necessary to perform a series of experiments, generating a comprehensive and complex amount of data.
The proposed sample size is sufficient to comply with the precision requirements of a complex sample that assumes a design effect of 1.5 and the prevalence of risk factors of interest of 5% or greater (Table 2).
The performance characteristics of the instrument were evaluated using a complex sample containing a mixture of fuel components, natural products, and organo-phosphorous compounds.
A complex sample design involving clustering of children within households and stratification of households within states based on the National Immunization Survey sampling plan was used to collect the data.
In addition, blood is a complex sample containing a variety of cells as well as many other components in the plasma.
However, unequivocal identification may be compromised using only oxonium and Y1 ions in a complex sample, because peptide backbones of different glycopeptides can generate the same mass even within a mass tolerance of 10 ppm.
We also evaluated the efficiency of dimethyl labeling on a complex sample by submitting 2 μg of total tryptic peptides from islets labeled by light and intermediate dimethyl reagents to nanoLC-MS analysis.
