Validation of the Sysmex XN analyser and Blood Bank mode for the quality and safety of donor blood and transfusion products.

OBJECTIVES: Our objective was to compare the measurement of residual white blood cell (rWBC) and residual red blood cell (rRBC) counts in blood products using the XN Blood Bank mode and the laboratory standard operating procedures for manual counts. In addition, to compare the whole blood complete blood count (CBC) values of blood donors and the quality of blood products using the Sysmex XN analyser versus the XS-1000i analyser. MATERIALS AND METHODS: For blood donors, 190 samples from blood or apheresis donors were analysed on both the Sysmex XS-1000i and XN-1000 analysers and the mean values of six CBC parameters were compared: the white blood cell count (WBC), the red blood cell count (RBC), haemoglobin (HGB), haematocrit (HCT), the mean corpuscular volume (MCV), the platelet count (PLT). For blood products, 164 samples were collected: 13 Plasma products - whole blood, 9 Plasma products - apheresis, 36 RBC concentrates - whole blood, 30 PLT concentrates - buffy coats, 36 PLT concentrates - buffy coats - pooled and 55 PLT concentrates - apheresis. RESULTS: All CBC parameters of the blood donors tested showed similar performance, with excellent correlation coefficients (r) ranging from 0.821 to 0.995. The majority of the blood products did not have a quantifiable number of residual cells, meaning the number of rWBC and rRBC, if present, was below the limit of quantitation (LoQ) of the different methods. rWBC were detected by Blood Bank mode in Plasma products - whole blood with a mean rWBC of 0.012 × 109 /L and in PLT concentrates - buffy coats with a mean rWBC of 0.19 × 109 /L. The correlation coefficient in both analysers for all three parameters (HGB, HCT, RBC) in RBC concentrates - whole blood was excellent, ranging from 0.95 to 0.99. For platelet count, r ranged from 0.98 to 0.99. CONCLUSION: The XN-Series analyser, equipped with a Blood Bank mode, demonstrated reliable performance when used for blood donor evaluation, rWBC enumeration and measurement of end blood products.

Performance evaluation of the new Sysmex XR-Series haematology analyser.

Background: The new XR-Series haematology analyser from Sysmex provides increased throughput and automation, along with a new reagent in WDF channel for optimised WBC differential. Methods: An analytical performance study for the XR analyser was conducted to evaluate the WDF channel parameters in comparison to the instrument specifications. Additionally, 7460 samples were measured on XR and XN analysers to compare selected parameters and flags, and 930 randomly selected samples were further evaluated with microscopy. Results: All investigated aspects of the analytical performance study for the XR fell within the manufacturer specifications. The correlation coefficients between the two systems for the parameters tested were greater than 0.983 for the main CBC and DIFF parameters, greater than 0.909 for the Extended Inflammation Parameters, and greater than 0.932 for the parameters used in the workflow rulesets of the Extended IPU. Similarly high sensitivities for the detection of abnormal cells were observed for the 'Blasts/Abn Lympho?' flag (XN: 100%, XR: 99.0%) and WPC abnormal flags ('Blasts?' or 'Abn Lympho?') (XN: 97.0%, XR: 96.0%). XN with WPC channel had a 26% reduction of false positive smears compared to XR with 22% reduction, a statistically non-significant difference. Conclusion: The XR analyser had very good analytical performance, and highly comparable results to the predecessor XN analyser in all investigated parameters, flags and workflow aspects.

Streptococcus thermophilus core genome: comparative genome hybridization study of 47 strains.

A DNA microarray platform based on 2,200 genes from publicly available sequences was designed for Streptococcus thermophilus. We determined how single-nucleotide polymorphisms in the 65- to 75-mer oligonucleotide probe sequences affect the hybridization signals. The microarrays were then used for comparative genome hybridization (CGH) of 47 dairy S. thermophilus strains. An analysis of the exopolysaccharide genes in each strain confirmed previous findings that this class of genes is indeed highly variable. A phylogenetic tree based on the CGH data showed similar distances for most strains, indicating frequent recombination or gene transfer within S. thermophilus. By comparing genome sizes estimated from the microarrays and pulsed-field gel electrophoresis, the amount of unknown DNA in each strain was estimated. A core genome comprised of 1,271 genes detected in all 47 strains was identified. Likewise, a set of noncore genes detected in only some strains was identified. The concept of an industrial core genome is proposed. This is comprised of the genes in the core genome plus genes that are necessary in an applied industrial context.