PMID- 31657495 OWN - NLM STAT- MEDLINE DCOM- 20200602 LR - 20200602 IS - 1939-165X (Electronic) IS - 0275-6382 (Linking) VI - 48 IP - 4 DP - 2019 Dec TI - The effects of storage at 4 degrees C and 20 degrees C on the hemograms of C57BL/6 mice and Wistar rats using the IDEXX ProCyte Dx and blood smear evaluations. PG - 652-667 LID - 10.1111/vcp.12784 [doi] AB - BACKGROUND: Delayed blood analysis might be unavoidable in laboratory practice, but little is known about rodent blood stability, especially cell morphology and scattergram results. OBJECTIVES: This study aimed to evaluate the stability of rodent blood cell counts and morphologies at different temperatures using the ProCyte Dx analyzer and performing manual observations. METHODS: Ten Wistar rats and 10 C57bl/6 mice were sampled on EDTA tubes and aliquoted for storage (4 degrees C, 20 degrees C). Hematologic analyses were performed immediately and at T6h, T24h, T48h (rats and mice), and T72h (rats only) after storage. RESULTS: In rats, at any temperature, red blood cell counts, hemoglobin concentrations (HGB), mean corpuscular hemoglobin (MCH) levels, and reticulocyte, white blood cell (WBC), eosinophil, and impedance platelet counts remained stable over time. The main changes were observed at 20 degrees C for hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and WBC differential counts. Optical platelet counts (PLT-O) and platelet variables underwent changes at both temperatures from T24h. In mice, red blood cell counts by impedance (RBC-I), MCH, and WBC, lymphocyte, eosinophil, and platelet counts, and plateletcrit (PCT) were stable over time and at all temperatures. As in rats, the most significant changes were observed at 20 degrees C and concerned the optical RBC (RBC-O) counts, HCTs, MCVs, MCHCs, and reticulocyte, neutrophil, and monocyte counts. For both species, blood cell morphologies were altered from T24h at all temperatures, and platelet clumps were more numerous at 4 degrees C. CONCLUSIONS: When rodent blood analyses need to be delayed, storage at 4 degrees C is preferred and should not exceed 24 hours. PLT counts should be interpreted cautiously in refrigerated specimens with mandatory blood smear evaluations when abnormal scattergrams are observed. CI - (c) 2019 American Society for Veterinary Clinical Pathology. FAU - Layssol-Lamour, Catherine AU - Layssol-Lamour C AD - Ecole Nationale Veterinaire de Toulouse, CREFRE, Universite de Toulouse, Inserm, UPS, ENVT, Toulouse, France. FAU - Lavabre, Typhaine AU - Lavabre T AD - Ecole Nationale Veterinaire de Toulouse, CREFRE, Universite de Toulouse, Inserm, UPS, ENVT, Toulouse, France. FAU - Braun, Jean-Pierre AU - Braun JP AD - Animal and Comparative Clinical Pathology, Toulouse, France. FAU - Trumel, Catherine AU - Trumel C AD - Ecole Nationale Veterinaire de Toulouse, CREFRE, Universite de Toulouse, Inserm, UPS, ENVT, Toulouse, France. FAU - Bourges-Abella, Nathalie AU - Bourges-Abella N AUID- ORCID: 0000-0002-0938-8131 AD - Ecole Nationale Veterinaire de Toulouse, CREFRE, Universite de Toulouse, Inserm, UPS, ENVT, Toulouse, France. LA - eng PT - Evaluation Study PT - Journal Article DEP - 20191028 PL - United States TA - Vet Clin Pathol JT - Veterinary clinical pathology JID - 9880575 SB - IM MH - Animals MH - Blood Cell Count/*instrumentation/*methods MH - Blood Preservation MH - Erythrocyte Indices MH - Mice MH - Mice, Inbred C57BL MH - Rats MH - Rats, Wistar MH - Temperature OTO - NOTNLM OT - hematology OT - mouse OT - preanalytical OT - rat OT - scattergrams OT - temperature EDAT- 2019/10/28 06:00 MHDA- 2020/06/03 06:00 CRDT- 2019/10/29 06:00 PHST- 2018/07/17 00:00 [received] PHST- 2019/01/14 00:00 [revised] PHST- 2019/01/19 00:00 [accepted] PHST- 2019/10/28 06:00 [pubmed] PHST- 2020/06/03 06:00 [medline] PHST- 2019/10/29 06:00 [entrez] AID - 10.1111/vcp.12784 [doi] PST - ppublish SO - Vet Clin Pathol. 2019 Dec;48(4):652-667. doi: 10.1111/vcp.12784. Epub 2019 Oct 28.