Development and preparation of a new serum protein reference material: feasibility studies and processing

Area of Science:

• Clinical Chemistry
• Biochemistry
• Analytical Chemistry

Background:

• Matrix reference materials are crucial for standardizing protein measurement immunoassays.
• The established ERM-DA470 reference material has significantly harmonized assay results since 1993.
• A new serum protein reference material, ERM-DA470k, has been developed to succeed ERM-DA470.

Purpose of the Study:

• To produce and characterize a new serum protein reference material, ERM-DA470k.
• To establish certification for beta(2)-microglobulin (B2M) in the new reference material.
• To evaluate the suitability of ERM-DA470k for standardizing protein immunoassays.

Main Methods:

• Pooled serum from 390 healthy donors was processed for stability, delipidation, and maturation.
• Purified C-reactive protein (CRP) and recombinant B2M were added to the serum pool.
• Pilot batches were produced and lyophilized to assess stability, homogeneity, and commutability.

Main Results:

• The new reference material (ERM-DA470k) demonstrated stability and commutability for B2M.
• A notable decrease of approximately 20% in measurable C-reactive protein (CRP) was observed after freeze-drying.
• The main batch met required criteria for optical transparency, homogeneity, and stability.

Conclusions:

• ERM-DA470k is a new serum protein reference material suitable for 14 proteins.
• The observed loss of CRP during freeze-drying requires consideration for its use in specific applications.
• This material aims to enhance the standardization of protein measurements in clinical diagnostics.