National Institute of Standards Technology Standard Reference

National Institute of Standards & Technology Standard Reference Material (SRM) 972 Vitamin D in Human Serum Intelimmune’s proprietary assay protocol for the vitamin D metabolites 25 hydroxy-vitamin D 2 and D 3 is fully validated by comparison with reference values supplied by the National Institute of Standards (NIST) for SRM 972. This standard reference material is intended for use as a control standard against which method accuracy may be measured. SRM 972 consists of four vials of frozen pooled serum each containing different reference concentrations for 25 hydroxy-vitamin D 2 and D 3, the vitamin D metabolites generally considered as reliable indicators of vitamin D status. It is standard policy that method accuracy assessments are routinely performed a minimum of once during each day that vitamin D assays are performed at Intelimmune. These quality checks will be conducted using either SRM 972 itself or other pooled reference material that has been standardized to SRM 972 and is traceable to within a single step removed from SRM 972. The table below contains averaged assay data from a recent. nine-replicate study of each of the four SRM 972 levels along with the associated NIST reference values for each level and metabolite: SRM Level 1 SRM Level 2 25 -(OH) VD 3 25 -(OH) VD 2 SRM Level 3 SRM Level 4 25 -(OH) VD 3 25 -(OH) VD 2 nmol/L nmol/L Average Conc. Values (Intelimmune) 63. 7 1. 5 33. 0 4. 5 49. 2 67. 3 88. 0 6. 8 Standard Deviation (Intelimmune) 2. 3 0. 2 1. 8 0. 5 2. 8 10. 6 2. 4 0. 7 NIST Reference Concentration 59. 6± 2. 1 1. 46± 0. 49 30. 8± 1. 5 4. 14± 0. 19 46. 2± 2. 8 64. 1± 4. 8 82. 3± 2 5. 8± 0. 52 Reference: NIST Certificate of Analysis for Standard Reference Material 972