[Performance verification of direct chemiluminescence immunoassay to detect the serum 25-hydroxyvitamin D...

To test the performance of direct chemiluminescence immunoassay(CLIA) in the determination of serum 25-hydroxyvitamin D [25(OH)D] concentration.

The CLIA analyzer of Italy DiaSorin was used to measure the 25(OH)D concentrations in the Standard Reference Material 972 a of National Institute of Standards and Technology, DiaSorin control materials, blind samples of Vitamin D External Quality Assessment Scheme(DEAQS), and outpatient serum samples. The functional sensitivity, precision, accuracy, recovery, and linearity were evaluated, and the samples of mild hemolysis, 5 days' storage at 4 ₿ and >1 year's storage at-80 ₿were tested for 25(OH)D.

The functional sensitivity was<4 ng/mL. The coefficient of variations of intra-and inter batch were<8. 1%. The relative deviation was-3. 1%-5. 7%. The recovery rates were 82. 8%-112. 9% and it had good linearity in the range of 7. 6-128. 1 ng/mL. Compared with fresh serum, the serum 25(OH)D concentration was not affected by mild hemolysis or being stored at 4 ₿for 5 days, but averagely decreased at 7. 6% by being stored at-80 ₿for more than 1 year. Compared with others, the deviation was-2. 9%-3. 6%. The differences in precision, accuracy and recovery of this method among the three different hospitals is slightly.

The performance of direct CLIA for 25(OH)D assay meet the basic technical requirements for laboratory medicine, and is laborsaving and timesaving.