A-069 Atellica® Ci 1900 Sample Carryover Performance Evaluation

Abstract

Abstract Background The Atellica® CI 1900 Analyzer uses independent integration and random-access sampling to process chemistry (CH) and immunoassay (IM) tests. A single-use, disposable sample tip is used for IM assays, whereas a reusable dilution probe is used for CH assays. When a sample tube is first accessed by the CH dilution probe to process CH assays, then accessed by the IM disposable tip to process IM assays, there is the potential for sample carryover that could affect IM assay results. The purpose of this investigation was to evaluate sample-to-sample carryover performance on the Atellica® CI 1900 Analyzer. Methods Hepatitis B surface antigen (HBsAg) was selected as the test analyte, given the extreme HBsAg concentrations that can exist in clinical samples. High HBsAg pools ranging from 25 to 55 million Index values were prepared by spiking purified HBsAg into serum. Eleven low (L) samples containing 600 µL of HBsAg-negative control QC and 10 high (H) samples containing 300 µL of the high HBsAg serum pool were created. The samples were first processed with one replicate per sample with the Atellica® CH ALT assay on the Atellica® CI 1900 Analyzer so that the CH dilution probe would aspirate 50 µL of sample. Sample-to-sample carryover testing was performed in a defined high (H)- and low (L)-sample consecutive sequence: L1, L2, L3, H1, H2, L4, H3, H4, L5, L6, L7, L8, H5, H6, L9, H7, H8, L10, H9, H10, L11. All low (L) samples were next assayed for HBsAg using the Atellica® CI 1900 Analyzer. The sample carryover study was conducted on three Atellica® CI 1900 Analyzers. Carryover in parts per million (ppm) was determined by multiplying the difference of the “high-low” mean (L4, L5, L9, L10, L11) and “low-low” mean (L2, L3, L6, L7, L8) by 1 000 000 and dividing by the high HBsAg sample concentration. Results The measured sample carryover results were 0.00, 0.00, and 0.00 ppm. All three Atellica® CI 1900 Analyzers produced sample-to-sample carryover of <0.1 ppm using HBsAg as the analyte. Conclusions The Atellica® CI 1900 Analyzer* demonstrated the capability to ensure sample-to-sample carryover of <0.1 ppm into primary sample containers with a minimum of 600 µL sample volume. *Not available for sale in the US. Product availability varies by country.