Scientific Concept of the National Cohort (status ... - Nationale Kohorte

A.3
A.3 Study design
Blood
In addition to the classic biological/medical data obtained by analysis of blood samples,
blood fractions (DNA, RNA, proteins, and metabolites) can also be analyzed by means of
high-throughput techniques available in the areas of genetics, transcriptomics, proteomics,
and metabolomics; thus, the analysis of blood samples will provide a wealth of new information
that will strengthen the molecular epidemiologic part of the National Cohort. Different
additives and preservatives are available to separate and obtain the different blood fractions
(plasma, serum, and cells). Apart from inhibitors of RNAses used to stabilize RNA, the
question of using stabilizing additives first needs to be viewed in the light of the processing
strategy pursued. Thus, inhibitors of glycolysis can be omitted if cells are instantaneously
removed from serum or plasma following blood specimen collection since the enzymes that
metabolize glucose are located in the cellular fraction. Similarly, avoiding the release of proteolytic
enzymes from leukocytes by avoiding mechanical cell lysis and cell lysis following
apoptosis upon prolonged transport needs to be considered first before considering the use
of protease inhibitors, such as aprotinin to inhibit the enzyme systems of leukocytes. Due to
the preanalytic processing in the local study centers, there is no need for most of these stabilizing
agents. However, blood collection tubes containing RNAse inhibitors will be used;
for plasma collection, ethylenediamine-tetra-acetic acid (EDTA)-coated tubes were chosen.
In addition, serum will be prepared from clotted whole blood.
Table 3.11: Biological samples: rationale for inclusion
Sample type Rationale Collection
Blood
Urine
Saliva
Stool
Swabs
> Different fractions available (plasma, serum, white cells,
red cells, and peripheral blood mononuclear cells)
> Different types of components present (cells, proteins,
DNA, RNA, hormones, nutrients, etc.)
> Suitable for a wide range of analytic procedures, including
-omics technologies
> Different types of components present (cells, proteins,
renal excretion products, etc.)
> Suitable for a wide range of analytic procedures, including
–omics technologies
> Provides additional (supplemental or new) information to
blood samples
> Provides specific information about oral microbiota
> Different types of components present (cells, proteins,
DNA, hormones, etc.)
> Suitable for several analytic procedures, including –omics
technologies
> Provides specific information about gut microbiota
> Suitable for several analytic procedures, including -omics
technologies
> Provides specific information about nasopharyngeal
microbiota
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> Easy, low risk, wellestablished,
standardized
procedures available
> Low costs of collection,
except for RNA
collection tubes and
BD 'CPT' tubes for
PBMC separation
> Easy, well-established,
standardized
procedures available
> Low costs
> Easy, well-established,
standardized
procedures available
> Low costs
> Issue of
standardization of
sample collection
> Specific logistics for
sample collection
necessary
> Standardized collection
according to SOPs