Sample preparation variation and its effects on automated blood cell differential analysis

Area of Science:

• Hematology
• Biomedical Engineering
• Laboratory Automation

Background:

• Uniform sample preparation is critical for accurate automated cell analysis.
• Variations in cell morphology due to inconsistent preparation can be misinterpreted as biological differences.
• The Abbott ADC-500 differential analysis system aims for automated, reproducible blood film preparation.

Purpose of the Study:

• To evaluate the impact of variations in spinning and staining parameters on the Abbott ADC-500 system.
• To quantify the effects on measured cell morphology and analyzer parameters.
• To ensure the reliability of automated differential analysis.

Main Methods:

• Testing automated blood film spinner and stainer modules for the ADC-500 system.
• Systematically varying spin speed, acceleration, deceleration, spin chamber configuration, post-spinning airflow, staining temperature, time, rinse volume, and stain:buffer ratios.
• Quantifying effects on measured leukocyte parameters and observed cell morphology.

Main Results:

• Spin time increased with hematocrit, consistent with prior reports.
• Spin speed and chamber configuration had minimal impact; post-spinning airflow significantly distorted morphology.
• Staining temperature critically affected erythrocyte morphology, while temperature, time, and rinse volume had minor effects on leukocyte parameters.
• Stain:buffer ratio influenced leukocyte parameters, with density increasing up to a 1:2 ratio.

Conclusions:

• The ADC-500 sample preparation modules operate within tighter parameter limits than tested variations.
• These modules do not introduce significant variations into the automated analyzer results.
• The system ensures reliable and reproducible cell analysis through consistent sample preparation.