5. Specimen collection for clinical laboratory investigation – major rules and requirements. Closed system for biological sample collection - advantages for the clinic, advantages for the clinical laboratory. Choosing a closed system according to the type of clinical laboratory analysis.

Specimen collection for clinical laboratory investigation – basic rules and requirements. Venous and capillary blood for analysis? Closed system for biological samples collection – advantages for the clinic, advantages for the laboratory.

Basic rules and requirements.

1. Blood, urine and other samples for examination are collected between 7-9 a.m. in the morning
2. Stop taking drugs (if possible).
3. Physical and psychological rest of the patient before and during the examination (procedure)
4. If possible, blood must be collected in a seated position of the patient, 15-20 min after seating. Hands should not hang down.
5. Strict observation of procedures of venipuncture, urine collection and collection of other biological samples.

Venous and capillary blood for analysis

Capillary blood is used for; (Arterial) blood gases, glucose, lactate, Newborns and little children, Necessity of repeated analysis for a short period of time, Impossibility of drawing a venous blood

It is not preferred to use capillary blood for analysis for the reason that capillary blood has lymph in it and is not with constant composition. The composition of the capillary blood depends on the blood flow towards the skin and the depth of pricking. In addition, hemoconcentration and acidosis are observed when there is a local stasis

The errors most commonly observed in capillary blood analysis are;

• Local acidosis: prolonged vein stasis (patients with severe diseases, immobilization, newborns)
• Not removing the first drop of capillary blood
• Wrong tubes/wrong anticoagulants/ citrate instead of EDTA /

Closed system for biological samples collection – advantages for the clinic, advantages for the laboratory

1. Safety for the patient and the staff
2. Evacuated tubes can be used directly for transportation and centrifugation of the blood sample
3. Evacuated tubes can be put directly in the instrument (analyzer) for testing the probe
4. Shorten the preanalytical stage in the laboratory
5. Correct ratio blood/anticoagulant
6. Shortened period for receiving the clinical-laboratory result