Laboratory analysis

Georg Alfthan

Selection of blood measurements

• Core measurements: • CVD risk factors

• Additional measurements: • CVD, Diabetes, Dietary biomarkers

• Infectious disease markers• Environmental exposure biomarkers

Critical pre-analytical issues of blood collection

• Fasting - 8-14 hours, glucose, triglycerides • Position of subject

• sitting• 10 min rest• lying 8% increase in blood volume

• Tourniquet - short duration• Season - spring vs. winter: cholesterol• Physical exercise

• heavy training dehydration

Documentation of blood collection

• ID of phlebotomist• Date and time of phlebotomy• Time from last meal• Number of tubes collected• Posture and reason if supine• Arm and reason if right

The procedure for specimen

collection, processing and storage

5

Type and order of blood tubes

1 2 3 4 5

SEER 1

FLS0

6 7 8

3 ml 4 ml 8 ml 4 ml9 ml

kääntö ↑↓ 18 kertaa

9 ml ml

LiHe

HbA1c

DNA1

DNA 2

SEER 2

8 ml

EDTA0

9 ml

Turn 18 times

Processing of blood tubes

Storage tubes

Storage tubes

Deep-freezing

Whole blood

analysis

Cryotube-20 C

Cryo Tube-70 C

Labelling of aliquots

Storage of specimen

• Short term storage = - 20°C- Core measurements

• Long term storage = - 70°C- Additional measurements

Responsibility of National HES Laboratory ?

Selection of National HES Laboratory

• All core measurements should be performed in the same lab: National HES Lab (NHESL)

• Selection criteria: performance in external quality assessment program (regular participation)

• Additional value: The lab is accredited by a national organization

Recommendation for analytical methods

• All analytical methods should be documented and validated

• Documentation should be available at National HES Laboratory (HESL) and EHES Reference Laboratory (RL)

Standardization of analytical data

• Pilot calibration

• • NHESL EHESRL

Reference samples

Analytical dataSatisfactory performance !

3

2

1

Performance of laboratories

Long term verification of bias

Bias of NHESL

Bias of EHESRL

CDC

National EQA program

Recommended goals for bias of methods

Bias (%)

Precision (CV%)• Core analytes Goal Acceptable

• Serum tot chol 3 5 2• Serum HDL chol 8 10 3• Plasma glucose 6 ? 3

Corrective measures recommended for National HES

Labs if bias exceeds criteria

• Check calibrators• Change reagents (kits)• Malfunctioning instruments• Wrong type of sample• Reagent not compatible with instrument

• Change method or technique !

Long term quality control

• Documentation of all changes done to methods and procedures

• Regular reporting to the central EHES RL