The Coulter Counter Model S Plus- the shape of things to come

Abstract

Summary The Coulter Counter Model S Plus is a 12 parameter haematological analyser designed for service use in haematology laboratories. Eight parameters are standard in current routine haematological practice; the seven parameters generated by the Model S and a platelet count. The method of platelet counting is unique. The remaining parameters are new and comprise the platelet‐crit, the mean platelet volume and size distribution measurements for both platelets and red cells. A description of the instrument is given including differences from the Model S. The new parameters are discussed in detail. Instrument precision is assessed in terms of linearity, reproducibility, drift, carry‐over and protein buildup. The results of all are impressive. Instrument accuracy is assessed in detail; white cell count, red cell count, haemoglobin concentration and mean corpuscular volume being compared with those values measured by the Model S; the Model S Plus haematocrit is compared with the microhaematocrit and platelet counts with those from the Thrombocounter C/Thrombofuge system. All correlations are very satisfactory. Normal values are defined for the new parameters. Instrument design and function are assessed and reagent consumption quoted. Cell control reagents have been evaluated. A realistic hourly throughput for the Model S Plus is 70–80 samples.

Does mean platelet volume influence the attack or attack-free period in the patients with Familial Mediterranean fever?

“…This results in an MPV that is lower than that found in normal subjects. This result was compatible with the findings of previous studies [22][23][24]. The low MPV in secondary thrombocytosis might be a result of this relation [21].…”

Comparative analysis of human ex vivo–generated platelets vs megakaryocyte-generated platelets in mice: a cautionary tale

“…Based on differences in organ size, [33][34][35] but with a similar degree of megakaryocyte entrapment, we estimate that 5% to 10% of entrapment occurred in the spleen (Figure 2C), but in no other studied tissue (supplemental Figure 3). Comparative confocal microscopy of human donor platelets circulating in mice blood and of released human platelets 2 hours after infusing AMC EV-megakaryocytes showed similar morphology, were equally greater in size than the mice platelets, [36][37][38] had discoid shape, and had a similar number and distribution of a-granules and lysosomes (supplemental Figure 4).…”

“…7,40 Murine platelets have approximately one third of the diameter of human platelets, with both displaying bell-shaped size distributions. [36][37][38] Whether higher shear forces in mice and differences in microvasculature contribute to small murine platelet size is unknown. We examined the size range (as determined by forward scatter on flow cytometry 41 ) of human platelets released from all 3 EVmegakaryocytes ( Figures 3A) and compared their size distribution to that of murine platelets and infused donor platelets.…”

Red Cell Distribution Width, Revisited

“…However, because of the technical difficulty in measuring red cell variability from the PBF, recently designed automated particle counters have allowed rapid and precise quantitation of volume heterogeneity. 3,4 Measured as a CV, red blood cell distribution width (RDW) is now an integral part of automated complete blood count (CBC) analysis and is available on all automated hematology analyzers.…”

“…8 The earliest method provided by the hematology analysis instruments to measure red cell variations is the RDW-CV. 3 During the past 3 decades, the clinical usefulness of this parameter has been studied in a wide range of hematological disorders. [9][10][11][12][13][14] Although many investigators 9,14,15,16,17 have advocated for the use of RDW along with MCV in delineating the probable cause(s) of each of the categories of micro-, macro-, and normocytic anemias, others 11,12,13,18 have doubted the usefulness of these parameters in the evaluation of micro-and macrocytosis.…”