Red Blood Cell Size Research Articles

Quantitative evaluation of microvascular blood flow by contrast-enhanced ultrasound (CEUS)

Ultrasound contrast agents consist of tiny gas-filled microbubbles the size of red blood cells. Due to their size distribution, they are purely intravascular tracers which do not extravasate into the interstitial fluid, and thus they are perfect agents for imaging blood distribution and flow. Using ultrasound scanners with contrast-specific software, the specific microbubble-derived echo signals can be separated from tissue signals in realtime, allowing selective imaging of the contrast agent. The signal intensity obtained lies in a linear relationship to the amount of microbubbles in the target organ, which allows easy and reliable assessment of relative blood volume. Imaging of the contrast wash-in and wash-out after bolus injection, or more precisely using the flash-replenishment technique, allows assessment of regional blood flow velocity. Commercially available quantification software packages can calculate time-related intensity values from the contrast wash-in and wash-out phase for each image pixel from stored video clips. After fitting of a mathematical model curve according to the respective kinetic model (bolus or flash-replenishment kinetics), time/intensity curves (TIC) can be calculated from single pixels or user-defined regions of interest (ROI). Characteristic parameters of these TICs (e.g. peak intensity, area under the curve, wash-in rate, etc.) can be displayed as color-coded parametric maps on top of the anatomical image, to identify cold and hot spots with abnormal perfusion.

Is Elevated Red Cell Distribution Width Associated with Colon Ischemia?

Purpose: Colon ischemia (CI) is thought to be caused by localized occurrences of non-occlusive vascular disease. Cases of stroke and congestive heart failure have been found to be associated with a high erythrocyte red cell distribution width (RDW), the altered red cell morphology possibly increasing blood viscosity and decreasing blood flow in the microcirculation. The purpose of this study was to see whether a similar association could be made with CI. Methods: We performed a retrospective review of the charts of 256 patients with biopsy-proven CI, evaluated their RDW's and compared them with the RDW's of 256 healthy patients referred for colonoscopy for indications other than anemia or bleeding. Patients were excluded from analysis if they had a known malignancy, advanced liver disease, chronic kidney disease requiring hemodialysis or if they had received a blood transfusion within 3 months prior to colonoscopy. The complete blood count closest to the day of colonoscopy was evaluated for each patient. An RDW of 14.2% or higher was considered elevated for this study. Data were compared using a chi squared analysis. Results: Patients with CI had a higher mean age (70.2 yrs) compared with the control group (58.9 yrs); both groups were relatively matched for gender (CI: 69.0% female; control: 64.8% female). An elevated RDW was observed in 105 patients (41.0%) with CI and 86 patients (33.6%) within the control group (p=0.083). Conclusion: Red cell distribution width, a reflection of the variability in circulating red blood cell size, when elevated, does not appear to confer an increased risk for colon ischemia.

Microbubble ultrasound compared to dynamic contrast MRI and CT for the assessment of vascular response to sunitinib in renal cell carcinoma.

e15039 Background: A novel ultrasound method employing microbubble (MB) contrast offers portable, noninvasive dynamic assessment of tumor blood flow. A MB contrast agent (Definity, Lantheus, Boston) is infused to produce vascular enhancement on nonlinear ultrasound imaging. The MBs, the size of red blood cells, remain intravascular. MBs are disrupted with an ultrasound pulse and the wash-in of new bubbles is imaged. This method, DCE-US, measures blood flow, velocity and vascular volume in multiple planes. Methods: Untreated patients (pts) with metastatic renal cell cancer (RCC) and a large abdominal tumor suitable for imaging were eligible for study and received Sunitinib 50 mg for 4 weeks on a 6-week cycle. DCE-US, contrast enhanced CT and DCE-MRI were performed on the first treatment course at baseline and on day 14. Blood samples for circulating endothelial cells (CECs) were obtained at the same time points. Results: The abdominal tumors imaged in 20 pts were the RCC primary (15pts), local recurrence (2), liver metastasis (1), retroperitoneal nodes (1) and a pancreas metastasis (1). In 16 pts progression free at 2 months, baseline vs. day 14 studies showed a significant (p < 0.05) decrease in blood volume in each of 13/16 pts (81%) on DCE-US, and a significant decrease in Ktrans and kep (Ktrans/ve) in 9/15 pts (60%) and 8/15 pts (53%) respectively on DCE-MRI. By RECIST criteria on CT, 3/16 (19%) and 13/16 (81%) were designated as partial response (PR) and stable disease (SD) respectively. By modified Choi criteria on CT, 8/13 (62%) and 5/13 (38%) were designated as PR and SD respectively. The number of viable CECs decreased in 10/14 (71%) and of apoptotic CECs in 9/14 (64%) pts. In 4 pts that progressed during the first sunitinib course, DCE-US showed a significant increase in blood volume in 1/4, no change in 2/4 and a decrease in 1/4. There was no increase in Ktrans or kep in progressing pts. The coefficient of variation of the same image plane scanned multiple times with DCE-US was 10%. Conclusions: DCE-US at 14 days is at least as good as DCE-MRI and a contrast enhanced CT at predicting progression-free survival at 2 months. This method is reproducible and takes advantage of a non-diffusible tracer. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Pfizer, Philips Ultrasound, Supersonic Imagine Inc. Pfizer Lantheus Medical Imaging, Inc., Pfizer

A multi-component lattice Boltzmann model with non-uniform interfacial tension module for the study of blood flow in the microvasculature

This study aims at analyzing the red blood cell (RBC) deformation and velocity while streaming through venules and through capillaries whose diameters are smaller than the RBC size. The characteristics of the RBC shape change and velocity can potentially help in diagnosing diseases. In this work, the RBC is considered as a surfactant-covered droplet. This is justified by the fact that the cell membrane liquefies under pressure in the capillaries, and this allows the marginalization of its mechanical properties. The RBC membrane is in fact a macro-colloid containing lipid surfactant. When liquefied, it can be considered as a droplet of immiscible hemoglobin covered with lipid surfactant in a plasma surrounding. The local gradient in the surface tension due to non-uniform local interface surfactant distribution is neglected here, and a non-uniform zonal-averaged value of surface tension representative of the surfactant bulk zonal concentration is rather implemented. The interplay between the surface tension geometry and the hydrodynamic conditions determines the droplet shape by affecting a change in its Weber number, and influences its velocity. The Gunstensen lattice Boltzmann model for immiscible fluids is used here since it provides independent adjustment of the local surface tension, and allows the use of fluids with viscosity contrast. The proposed concept was used to investigate the dynamic shape change of the RBC while flowing through the microvasculature, and to explore the Fahraeus and the Fahraeus–Lindqvist effects. Copyright © 2010 John Wiley & Sons, Ltd.

Dramatic recovery from severe anemia by resolution of severe periodontitis

Periodontal infections were previously found to be associated with systemic diseases such as diabetes, stroke, cardiovascular disease, bacterial pneumonia, and preterm low births. Individuals with gum disease have increased concentrations of circulating inflammatory markers that contribute to systemic inflammation, and periodontitis may tend towards anemia because of depressed erythropoiesis. Anemia of chronic disease (ACD) is defined as anemia that occurs during infections, inflammation, neoplasia, and a wide range of diseases including renal, endocrine and cardiovascular diseases. The etiology of ACD is multifactorial, but is often under-recognized and undertreated. This article describes an unusual case of severe anemia caused by severe periodontitis in a 50-year-old woman. After extracting many hopeless teeth, resolving the periodontitis and making new dentures, a dramatic recovery from the severe anemia was obvious 4 months later, and her health-related quality of life vastly improved. All blood values returned to normal with no medication. Chronic periodontitis can be a cause of ACD. The diagnosis of ACD based on the mean size and heterogeneity of red blood cells and an iron study, such as serum iron and ferritin, is discussed.

Effect of oral immunization with pooled antigens derived from adipose tissue on atherosclerosis and obesity indices

Modulation of the inflammatory response through vaccination has shown promise in animal models of atherogenesis and obesity—main risk factors for cardiovascular diseases. Tableted preparation, V-6, containing pooled antigens derived from pig adipose tissue was administered per os daily to 13 volunteers for 3 months. Total cholesterol and LDL levels have not changed from the baseline value; 193.4 vs 191.8 ( p = 0.75) and 113.8 vs 117.2 ( p = 0.18), respectively. Triglyceride levels declined by 26.1% from 163 to 120.5 mg/dL ( p = 0.29). HDL increased by 25.9% from 38.6 to 48.5 mg/dL ( p = 0.000002) in 12 out 13 patients. Despite negligible effect of V6 on weight and body mass index, i.e., 67.87 vs 66.58 kg (−1.9%; p = 0.46) and 26.25 vs 25.75 kg/m 2 (−1.9%; p = 0.35), statistically significant reduction in waist (−7.6%; p = 0.002), mid-arm (−3.3%; p = 0.049), and thigh (−7.6%; p = 0.0003) circumferences were observed. Blood pressure systolic and diastolic values were not affected, i.e., 115.6 vs 121 ( p = 0.2) and 77.1 vs 83 ( p = 0.55). No changes were observed in liver ALT and AST enzymes. Creatinine decreased; 0.877 vs 0.842 mg/dL ( p = 0.02), while BUN has shown slight increase; 14.8 vs 16.1 mg/dL ( p = 0.03) but within normal range. Fasting blood sugar levels were also within normal range, i.e., 94.8 vs 98.8 ( p = 0.04). Complete blood cell analysis has not revealed any change except slight decrease in hemoglobin 13.25–13.19 g/dL ( p = 0.0004), but its amount per red blood cell (MCH) increased from 25.62 up to 26.42 picograms/cell ( p = 0.000003). The average red blood cell size (MCV) increased from 78.5 to 80.0 fl ( p = 0.00009) but hemoglobin concentration relative to size of the cell (MCHC) has not changed ( p = 0.2). Hematocrit and red blood cells count decreased slightly, but within normal range 40.7–40.2% ( p = 0.02) and 5.22–5.05 × 10 6 cells/mm 3 ( p = 0.002). The number of platelets moved upward, 2.471 vs 2.921 × 10 5 per mm 3 ( p = 0.009). The white blood cells count and percent of leukocytes and neutrophils were not affected. Pro-inflammatory eosinophils declined from 4.0% down to 2.4% ( p = 0.29). These results show that V6 is safe and holds a promise as an anti-atherogenic and overweight/obesity immune intervention.

Changes in Red Blood Cell Size and Red Cell Fragmentation during Hemodialysis

Intradialytic hypotension remains the commonest complication for outpatient hemodialysis. The majority of relative blood volume (RBV) monitoring techniques monitor changes in hematocrit. As hematocrit can potentially be affected by changes in red cell size and hemolysis we studied the change in red blood cell size (MCV) during dialysis and hemolysis. MCV was prospectively measured in 176 stable regular adult hemodialysis outpatients (56% male, 27.8% diabetic, mean age 59.5 ±16.2 years) dialyzing against a range of dialysate sodiums (136-145 mmol/L), with cooled dialysate (35-36°C), containing 1 g/L glucose, with constant ultrafiltration profiles. Red cell fragmentation was studied in 41 of the cohort. Logistical regression analysis showed that the absolute change in MCV was related to the change in hematocrit (F=4.92, β=0.111, p=0.031), and inversely with red cell shrinkage associated with predialysis osmolality (F=5.06, β=0.83, p=0.029), and dialysate sodium (F=4.7, β=0.34, p=0.035). There was no significant increase in red cell fragments during the dialysis sessions. Indirect assessment of RBV based upon the relative change in hematocrit, depends not only upon the change in plasma water and red blood cell numbers, but also upon MCV. Changes in MCV may theoretically lead to potential effects on RBV measurements.

Clinical utility of the new beckman‐coulter parameter red blood cell size factor in the study of erithropoiesis

CHr has been used as a diagnostic tool, together with biochemical markers, to distinguish IDA from ACD, and is incorporated to NKF-K/DOQI guidelines for the monitoring of rHuEPO therapy. The measurement of CHr has been restricted to the analysers of a single manufacturer, Siemens. Red blood cell size factor (RSf) is a new parameter provided by Beckman-Coulter which joins together the volume of erythrocytes and the volume of reticulocytes Rsf = square root (MCV x MRV). The aims of the study were to establish the values of RSf in normal population and in different types of anemia to investigate its clinical usefulness in the study of erythropoiesis and its correlation with CHr. Samples from 449 patients (learning group) were run sequentially on both LH 750 (Beckman-Coulter) and Advia 2120 (Siemens) analysers. Good correlation between CHr and RSf was observed, r(2) = 0.85. Receiver operating characteristic curve analysis for RSf and the diagnosis of restricted erythropoiesis. [table: see text] The diagnostic usefulness of RSf was evaluated on a validation group which included 220 consecutive patients with anemia. This study shows a very good level of agreement between RSf and CHr. Both are suitable parameters for the study of erythropoiesis.

The smallest avian genomes are found in hummingbirds

It has often been suggested that the genome sizes of birds are constrained relative to other tetrapods owing to the high metabolic demands of powered flight and the link between nuclear DNA content and red blood cell size. This hypothesis predicts that hummingbirds, which engage in energy-intensive hovering flight, will display especially constrained genomes even relative to other birds. We report genome size measurements for 37 species of hummingbirds that confirm this prediction. Our results suggest that genome size was reduced before the divergence of extant hummingbird lineages, and that only minimal additional reduction occurred during hummingbird diversification. Unlike in some other avian taxa, the small amount of variation observed within hummingbirds is not explained by variation in respiratory and flight-related parameters. Unexpectedly, genome size appears to have increased in four unrelated hummingbird species whose distributions are centred on humid forests of the upper-tropical elevational zone on the eastern slope of the Andes. This suggests that the secondary expansion of the genome may have been mediated by biogeographical and demographic effects.

Estimation of human red blood cells size using light scattering images

In this paper, a novel method for the estimation of the human Red Blood Cell (RBC) size using light scattering images is presented. The information retrieval process includes, image normalization, a two-dimensional Discrete Cosine Transformation (DCT2) or Wavelet transformation (DWT2), and a Radial Basis Neural Network (RBF-NN) estimates the RBC geometrical properties. The proposed method is evaluated in both regression and identification tasks when three important geometrical properties of the human RBC are estimated using a database of 1575 simulated images generated with the boundary element method. The experimental setup consists of a light beam at 632.8 nm and moving RBCs in a thin glass and additive noise distortion is simulated using white Gaussian noise from 60 to 0 dB SNR. The regression and identification accuracy of actual RBC sizes is estimated using three feature sets, giving a mean error rate less than 1 percent of the actual RBC size, in case of noisy image data at 10 dB SNR or better, and more than 97 percent mean identification rate.

Red blood cell quantification microfluidic chip using polyelectrolytic gel electrodes

This paper reports on a novel microfluidic chip with polyelectrolytic gel electrodes (PGEs) used to rapidly count the number of red blood cells (RBCs) in diluted whole blood. The proposed microdevice is based on the principle that the impedance across a microchannel between two PGEs varies sensitively as RBCs pass through it. The number and amplitude of impedance peaks provide the information about the number and size of RBCs, respectively. This system features a low-voltage dc detection method and non-contact condition between cells and metal electrodes. Major advantages include stable detection under varying cellular flow rate and position in the microchannel, little chance of cell damage due to high electric field gradient and no surface fouling of the metal electrodes. The performance of this PGEs-based system was evaluated in three steps. First, in order to observe the size-only dependence of the impedance signal, three different sizes of fluorescent microbeads (7.2, 10.0, and 15.0 mum; Bangs laboratories, USA) were used in the experiment. Second, the cell counting performance was evaluated by using 7.2 mum fluorescent microbeads, similar in size to RBCs, in various concentrations and comparing the results with an animal hematoanalyzer (MS 9-5; Melet schloesing laboratories, France). Finally, in human blood sample tests, intravenously collected whole blood was just diluted in a PBS without centrifuge or other pretreatments. The PGE-based system produced almost identical number of RBCs in over 800-fold diluted samples to the results from a commercialized human hematoanalyzer (HST-N402XE; Sysmex, Japan).

Estimation of human red blood cells size using light scattering images

In this paper, a novel method for the estimation of the human Red Blood Cell (RBC) size using light scattering images is presented. The information retrieval process includes, image normalization, ...

Red Blood Cell Distribution Width and Mortality Risk in a Community-Based Prospective Cohort

Red blood cell distribution width (RDW), an automated measure of red blood cell size heterogeneity (eg, anisocytosis) that is largely overlooked, is a newly recognized risk marker in patients with established cardiovascular disease (CVD). It is unknown whether RDW is associated with mortality in the general population or whether this association is specific to CVD. We examined the association of RDW with all-cause mortality and with CVD, cancer, and chronic lower respiratory tract disease mortality in 15 852 adult participants in the Third National Health and Nutrition Examination Survey (1988-1994), a nationally representative sample of the US population. Mortality status was obtained by matching to the National Death Index, with follow-up through December 31, 2000. Estimated mortality rates increased 5-fold from the lowest to the highest quintile of RDW after accounting for age and 2-fold after multivariable adjustment (P(trend) < .001 for each). A 1-SD increment in RDW (0.98%) was associated with a 23% greater risk of all-cause mortality (hazard ratio [HR], 1.23; 95% confidence interval [CI], 1.18-1.28) after multivariable adjustment. The RDW was also associated with risk of death due to CVD (HR, 1.22; 95% CI, 1.14-1.31), cancer (1.28; 1.21-1.36), and chronic lower respiratory tract disease (1.32; 1.17-1.49). Higher RDW is associated with increased mortality risk in this large, community-based sample, an association not specific to CVD. Study of anisocytosis may, therefore, yield novel pathophysiologic insights, and measurement of RDW may contribute to risk assessment.

Variation in erythrocyte size between juveniles and adults of Odontophrynus americanus

Abstract Differences in erythrocyte size between tadpoles and adults have been found in numerous anuran species but there are no references about erythrocyte size of juveniles. We measured the size of red blood cells and nuclei of juvenile and adult individuals of Odontophrynus americanus. Erythrocyte and nuclear size of juvenile were significantly smaller than the corresponding sizes of adults. The erythrocytes of juvenile O. americanus were comparable in size to the erythrocytes of adult O. cordobae. We discuss about the possibility of correctly distinguishing juvenile O. americanus (tetraploid) from adult O. cordobae (cryptic diploid counterpart) specimens using erythrocytes. We also discuss possible causes of variation.

Shape and size of red blood cells from the Pygoscelid penguins of Antarctica using atomic force microscopy

Antarctic biodiversity is evolutionarily com- plex, reXecting the extreme ambient conditions. Therefore, Antarctic organisms exhibit sophisticated adaptations in all organization levels, including organs, tissues, and cells. Since red blood cells (RBCs) travel through the vertebrates blood delivering O2 to all tissues and organs and purging the unwanted CO 2 , they represent an interesting model to investigate biological adaptations. We have used atomic force microscopy (AFM) to compare the shape and size of RBCs of the Pygoscelid penguins. A total of 18 landmarks were measured in AFM images. When analyzed individu- ally, the parameters were not capable of discriminating the RBCs of each species. However, the simultaneous use of multiple parameters discriminated (74%) among the RBCs. In addition, the use of RBC measurements was suYcient to hierarchically cluster the species in accordance to other common and reliable phylogenetic strategies. In light of these results, the use of RBC characters could eVectively beneWt taxonomic inferences.

Erythrocyte indices in relation to hydration and electrolytes in horses performing exercises of different intensity

Exercise induces changes in hydration and electrolytes status that might affect volumetric properties of erythrocytes. This research analyzes the modifications induced for different type of exercises on volumetric indices in horses in relation to plasma electrolytes, total plasma proteins, heart rate, and lactate. One hundred sixty-four healthy sport horses were studied, divided into six groups: A (16 racing Angloarabians), B (12 jumping Angloarabians), C (45 endurance horses), D (18 Andalusians), E (65 draft horses), and F (eight eventers). In groups A, C, E, and F, blood samples were taken before and after competition. The horses of groups B and D were subjected to an exercise test and blood samples were taken before and after the test. The parameters analyzed were: packed cell volume (PCV), mean cell volume (MCV), mean cell hemoglobin (MCH), mean cell hemoglobin concentration (MCHC), Na, K, Cl, heart rate, total plasma proteins, and plasma lactate concentrations. PCV increased in all the groups, MCV decreased in group D, MCH increased in groups D and F and decreased in group E, and MCHC increased with exercise in groups A and F. The only significant correlation between plasma electrolyte and volumetric indices was found between plasma Na concentrations and MCV. It is concluded that, although volumetric indices change with exercise in horses, their modifications are somewhat erratic and do not show a direct correlation with hydration, electrolyte status and exercise intensity, but red blood cell size is partially dependent on plasma Na concentration.

On the validity of Rayleigh–Gans–Debye type approximations in red blood cell size determination

The validity of the Rayleigh-Gans-Debye (RGD) approximation for the size determination of a soft prolate spheroidal scatterer has been examined. Calculations have been carried out for the volume range 30–100 µm3 and for aspect ratios ranging from 1.1 to 4.0. Particular attention has been paid to size determination of a red blood cell (RBC) in a flow cytometric arrangement. The applicability of the RGD approximation has been compared with its two modified forms and also with the WKB approximation.

Genome size, cell size, and the evolution of enucleated erythrocytes in attenuate salamanders

Within the salamander family Plethodontidae, five different clades have evolved high levels of enucleated red blood cells, which are extremely unusual among non-mammalian vertebrates. In each of these five clades, the salamanders have large genomes and miniaturized or attenuated body forms. Such a correlation suggests that the loss of nuclei in red blood cells may be related, in part, to the interaction between large genome size and small body size, which has been shown to have profound morphological consequences for the nervous and visual systems in plethodontids. Previous work has demonstrated that variation in both the level of enucleated cells and the size of the nuclear genome exists among species of the monophyletic plethodontid genus Batrachoseps. Here, we report extensive intraspecific variation in levels of enucleated red blood cells in 15 species and provide measurements of red blood cell size, nucleus size, and genome size for 13 species of Batrachoseps. We present a new phylogenetic hypothesis for the genus based on 6150 bp of mitochondrial DNA sequence data from nine exemplar taxa and use it to examine the relationship between genome size and enucleated red blood cell morphology in a phylogenetic framework. Our analyses demonstrate positive direct correlations between genome size, nucleus size, and both nucleated and enucleated cell sizes within Batrachoseps, although only the relationship between genome size and nucleus size is significant when phylogenetically independent contrasts are used. In light of our results and broader studies of comparative hematology, we propose that high levels of enucleated, variably sized red blood cells in Batrachoseps may have evolved in response to rheological problems associated with the circulation of large red blood cells containing large, bulky nuclei in an attenuate organism.

Correlation of Red Blood Cells and Platelets Parameters.

INTRODUCTION: Platelet along with red blood cell count is a part of complete blood cell count, one of the most frequent laboratory tests in medicine. Platelet distribution width, plateletcrit and mean platelet volume are three indices provided by hematological analyzers. There are few reports in literature regarding the correlation of these three parameters with red blood cell parameters.AIM: Aim of this study is to investigate the correlation between these platelets parameters and red cell parameters: hematocrit, mean corpuscular volume and red blood cell distribution width.METHODS: Three hundred and three healthy blood donor volunteers (176 men and 127 women, mean age 37,3 years) were included. None of them had any known hematological disease in the past. The parameters mentioned above were measured by the automated hematological analyzer Coulter®LH780.RESULTS: The mean values for platelets were: PCT: 0,25±0,11%, MPV: 8,11±1,94 fL and PDW: 15,89±2,74%. The mean values for their parallel red blood cell parameters were: HCT: 40,55±2,63%), MCV: 91±4,17 fL, RDW: 13,3±1,35% Statistical and regression analysis including the correlation coefficient between platelet and red cell parameters as well as Student's t-test was carried out.CONCLUSIONS:a.There seems to be no significant correlation between HCT and PCT. MCV and MPV were not correlated significantly as well, indicating that red blood cell and platelet sizes are independent. But there is a statistically significant correlation between RDW and PDW (r: 0,68, p<0,01) demostrating that anisocytosis of red blood cells and platelets might occur simultaneously.b.Based on these observations, further more studies should be carried out for the correlation between platelets and red blood cell indices in certain disorders.

High-Speed Mass Analysis of Whole Erythrocytes by Charge-Detection Quadrupole Ion Trap Mass Spectrometry

Herein, we report an application of charge-detection quadrupole ion trap mass spectrometry to the measurement of total dry masses of mammalian and poultry erythrocytes evaporated/ionized by laser-induced acoustic desorption. The method is rapid and widely applicable. Eight different types of red blood cells (RBCs) have been successfully analyzed, including those of human, goat, cow, mouse, pig, and chicken. The measured mean masses (weights per corpuscle) range from 0.58 x 10(13) Da (9.6 pg) of goat RBCs to 2.80 x 10(13) Da (46.5 pg) of chicken RBCs. The total dry weights determined for human RBCs from a healthy male adult, a patient with iron-deficiency anemia, and a patient with thalassemia are 34.8, 28.8, and 20.6 pg, respectively. These weights, except that of thalassemia, are all approximately 10% higher than their corresponding mean corpuscular hemoglobin values determined by a commercial automated hematology analyzer. The mass distribution profiles of the cells are all near-Gaussian, with a standard deviation of 15% for the normal human RBCs. The deviation increases significantly to 20% for RBCs with thalassemia characteristics and 27% for RBCs with iron-deficiency anemia characteristics. All the observations are in accord with their corresponding mean corpuscular volume measurements, indicating an increase in anisocytosis (variation in RBC size) in the anemic samples. Our results suggest a broad and promising application of this new technology to high-speed mass analysis of RBCs and other biological whole cells as well.