Serum and Plasma Collection: Preanalytical Variables and Standard Operating Procedures in Biomarker Research - Proteomic and Metabolomic Approaches to Biomarker Discovery - page 78

TABLE 1 Preanalytical Variables to Consider When Establishing Standard Operating Procedures

Preanalytical factors Examples to consider

Source of sample
biological variables

Disease or control, comorbidities, age, gender, medications, fasting status, recruitment
location (clinic, procedure), skill of phlebotomist, race, medical history

Sample type (serum,
plasma, cells)

Serum, plasma with platelets, platelet-free plasma, buffy coat, peripheral blood mononuclear
cells

Volume
collected/
analyzed

Impact on subject s health, storage space, costs, resources, long-term aims, reproducibility,

replicates, future use in other platforms

'

Additive type Proper mixing, no additive, clot activator, EDTA, heparin, thrombin, sodium citrate, acid

citrate dextrose, potassium oxalate

Glass or plastic tubes Proteins adhering to plastic, leaching from plastic into blood, breakage, BBP risks, local

regulations, cost

Temperature: stability Dependent on additive; room temperature, cold (wet ice), refrigerated

Transport logistics Dependent on additive; room temperature, cold (ice), upright, dark, minimal jostling

Dependent on analyte of interest; room temperature, 4 C (refrigerated centrifuge) Temperature: processing

Time Dependent on analyte of interest and specimen type; minimize time not stabilized, minimize

time to processing, minimize time from processing to final storage, annotate

Time in storage Age of sample, amount of time in storage, sublimation of specimen, variations in temperature

during storage time

Dependent on analyte of interest; 4 C, e 20 C, e 70 C, e 80 C, liquid nitrogen Temperature: storage

Fixed rotor or bucket, 4 C (refrigerated), maximum g, adjustable brake setting, size of tubes
allowed (volume)

Centrifuge requirements

Protection from light Required or not.

Other precautions Universal precautions for blood-borne pathogens (BBP), biosafety levels for known infectious

agents, exposure plan for BBP

Hemolyzed, icteric,
lipemic

Annotate if observed

Aliquots: tubes Dependent on storage temperature and desired volume; cryogenic, temperature-speci c,

minimize cracking or expansion due to temperature, volume, or material

Aliquots: labeling Permanent marker or label speci c for the temperatures, barcode or sample ID, date,

specimen type

Aliquots: volume Dependent on volume needed per assay, storage space, long-term aims, micro-aliquots

( 500 l), replicates needed, sublimation of specimen

< m

Aliquot: storage logistics Freezer management and sample tracking, racks, boxes, freezer maps to locate samples,

standard sized tubes to fit in standard racks and boxes

Transport of aliquots Shipping or transporting on wet ice, dry ice, manifests or packing lists, handling frozen

samples on dry ice, Department of Transportation (DOT) and International Air Transport
Association (IATA) regulations for shipping on dry ice

Freeze-thaw parameters Track freeze-thaw cycles. Choose appropriate aliquot volumes to avoid repeated freeze-thaw