Electronic Cell Counter Research Articles

Temperature adaptation of the growth and division process of Tetrahymena pyriformis: II. Relationship between cell growth and cell replication

Replication rates and volume distributions of Tetrahymena pyriformis GL determined with a commercially available electronic cell counter are reported for several temperatures. Tetrahymena pyriformis GL was cultured in proteose peptone yeast extract medium at 28.0, 30.8, 32.5, and 33.9 °C. During the period of exponential cell replication at all temperatures, the volume distribution was constant, lognormal and the standard deviation from the median volume was temperature independent. This indicates a steady state of balanced growth at 28.0, 30.8, and 32.5 °C during exponential cell replication. It is demonstrated that the knowledge of volume distribution and generation time is insufficient for calculating rates of cell growth between divisions unless the parameters for the momentary volume distribution can be measured independently. Statistical evaluation of data from the literature confirms previously reported findings which indicate that growth of Tetrahymena over extended periods of the division cycle is approximately exponential and not linear. The previous proposition that control mechanisms for growth of Tetrahymena and Paramecium are different, is thus unnecessary. A new model, which describes the control of cell growth and cell replication is suggested. The model accounts for the lognormal distributions of generation times and volumes as well as the nearly exponential rate of growth between divisions. The mean rate of cell replication which decreases with increasing temperatures above the optimum rather than all temperatures shows a negative correlation with the median log volume of the culture. This is in accordance with the predictions of the proposed growth model and furthermore indicates that the growth rate is to a large extent independent of cell replication.

Temperature adaptation of the growth and division process of Tetrahymena pyriformis: I. Adaptation phase

Growth rates of Tetrahymena pyriformis GL are reported following temperature shifts and during induction of synchronous cell division. Use of an electronic cell counter permitted the ready determination of cell volume distributions. These distributions were used in determining growth rates. Tetrahymena pyriformis GL was cultured in proteose peptone yeast extract medium at 28.0, 30.8, 32.5, and 33.9 °C. Following a temperature shift from 28 °C to a higher temperature, a brief period of continued cell division occurred followed by a prolonged period of blocked cell division. Division block was permanent at 33.9 °C and was of a temporary nature during the temperature adaptation phase at 30.8 and 32.5 °C. Correlation coefficients of the growth rates suggest that cell growth during temperature adaptation was exponential. Cell volumes were log-normally distributed before the temperature shift and during periods of temperature adaptation. The slope of the log volume class distribution was constant with time during the period of inhibited cell division. During induction of synchronous division, produced by intermittent heat shocks, cell growth was also exponential, cell volumes were log-normally distributed and the slope of the log volume class distribution was constant. This constancy in slope during periods of inhibited cell division indicates that the rate of cell growth is independent of the division cycle during single and multiple temperature adaptation. During periods of inhibited cell division the rate of cell growth at 30.8 °C was significantly different from that at 32.5 °C. However, the rate of growth at 33.9 °C was significantly lower than at 30.8 or 32.5 °C. This indicates that the optimum temperature for the rate of cell replication and growth are different.

Compendium of normal blood values of laboratory animals, with indication of variations: I. Random-sexed populations of small animals

Blood has been collected from five species of laboratory animals and analyzed by ultramicro, micro, and automated techniques; the data have been analyzed statistically. Data obtained with the ultramicroanalytical system indicate that difficulties have been substantially overcome in handling minute quantities of biological fluids obtained from small laboratory animals. The degree of correlation between electronic blood cell counts and the actual visualization of the cells in the counting chamber of the hemacytometer has been accepted as a demonstration that the electronic counts reflect the level of cellular components in the sample.

Quantitation of mouse femoral and tibial marrow using an electronic cell counter.

SummaryA method of quantitating the cellularity per mg of mouse marrow with the Coulter electronic cell counter is described and the absolute numbers of each cell type in the left and right femurs and tibias have been determined. It was found that the cellularity per mg of marrow in the 4 long bones of the hind legs did not differ significantly.

Comparison of the growth of fibroblasts under the influence of 11-betahydroxy and 11-keto corticosteroids.

Fibroblasts of Clone 929-L were incubated in the presence of various concentrations of corticosteroids and quantitative measurements of cell growth were made by means of an electronic cell counter. It was found that the 11β-OH corticosteroids, cortisol, 2-methylcortisol, prednisolone, and corticosterone markedly inhibited fibroblast proliferation, whereas the 11-keto compounds, cortisone, 2-methylcortisone, prednisone, and 11-dehydrocorticosterone allowed fibroblast growth equal to or greater than control levels. 11-Desoxy compounds, 11-desoxycortisol and 11-desoxycorticosterone, caused cellular proliferation midway between that caused by 11β-OH and 11-keto compounds. Metabolic studies with cortisol-l,2-3H and cortisone-4- 14C showed that there was no interconversion between cortisone and cortisol when these substances were incubated with actively metabolizing strain L fibroblasts in cell culture. Therefore, although fibroblasts in connective tissue have an active 11β-OH dehydrogenase system, tissue cultu...

Osmotic adaptation of mouse lymphoblasts.

Abstract 1. 1. Osmotic adaptation in a tissue-cultured mammalian cell, the L5178-Y mouse lymphoblast, has been studied by means of an electronic cell counter coupled with a pulse-height analyzer system. 2. 2. It was found that these cells first swell and then ultimately return to normal size in various dilutions of medium. Also, cells remain viable after the temporary shock of these dilutions. 3. 3. An empirical equation has been computer-fitted to the data. A permeability constant for water has been obtained, 0.83 ± 0.05 μ 3 per min per μ 2 of cell surface per atm difference in osmotic pressure, which checks closely with other cells with the same surface-to-volume ratio of 0.55 μ −1 . Possible explanations for the swelling and shrinking phenomenon are offered.

Evaluation of Electronic Measurements of Hemagglutination for Quantitative Studies

Summary The results of an extensive study of the use of total particle measurements obtained by an electronic cell counter for quantitative hemagglutination purposes are presented. Total particle data were shown to yield nonlinear log probit and logit log assay curves. The free cell to total particle relationship was shown to differ with the avidity of the serum and the strength of the antigen on the red cell within a system, and with the pattern of aggregation among blood group systems. It is therefore doubtful that total particle measurements have any useful application in quantitative hemagglutination assay systems.

Cell counts of mouse bone marrow

An electronic cell counter has been used to quantify the numbers of bone marrow cells in the mouse tibia. Preliminary experiments have revealed that a single injection of a bacterial endotoxin causes a significant decrease in the absolute numbers of mature neutrophils from the bone marrow after 5 hours and a partial recovery to normal values after 22 hours.

RAPID ADHESIVE PLATELET COUNT IN WHOLE BLOOD.

A proportion of the platelets in whole blood become more adhesive when treated with adenosine diphosphate. After these platelets have adhered to the walls of a polystyrene container, E.D.T.A. is added and a count is made of the remaining platelets in the blood sample. By subtracting this latter count from the total whole blood platelet count a whole blood adhesive platelet count is obtained. For rapidity and accuracy, an electronic cell counter is used for each platelet count.

A quantitative assessment of mouse thymus differentiation

1. 1. A method is described for the quantitative assay of lymphoid differentiation using an electronic cell counter and size analyzer. 2. 2. Using this method, the normal in situ differentiation of the prenatal and early postnatal mouse thymus has been described in terms of increase in lymphocyte number and decrease in cell size. 3. 3. The implications of the results are briefly discussed.

Observations on the use of the Coulter model D electronic cell counter in clinical haematology

Observations on the use of the Coulter model D electronic cell counter in clinical haematology

Observations on the use of the Coulter model D electronic cell counter in clinical haematology.

The use of the Coulter electronic cell counting machine (model D) in a routine pathological laboratory is described, as are also the technical details involved.

A Practical Diluent for Electronic White Cell Counts

A Practical Diluent for Electronic White Cell Counts Get access Giovanni D'Angelo, Giovanni D'Angelo 1Department of Hematology, Maisonneuve, Montreal, Canada Search for other works by this author on: Oxford Academic Google Scholar Michel Lacombe, M.D. Michel Lacombe, M.D. 1Department of Hematology, Maisonneuve, Montreal, Canada Search for other works by this author on: Oxford Academic Google Scholar American Journal of Clinical Pathology, Volume 38, Issue 6_ts, December 1962, Pages 658–662, https://doi.org/10.1093/ajcp/38.6_ts.658 Published: 01 December 1962 Article history Received: 25 May 1962 Accepted: 20 August 1962 Published: 01 December 1962

Blood cell counting: a comparison of the E.E.L. and Coulter machines.

1. The performance of two electronic blood cell counting machines has been extensively tested under routine working conditions in a busy hospital laboratory.

Measurement of red blood cell volume with the electronic cell counter.

Measurement of red blood cell volume with the electronic cell counter.

An Electronic Blood-Cell-Counting Machine

Abstract An electronic blood cell counting machine operating on a flow principle is described. It is quick and easy to use; it can perform a red cell count in ten seconds with an accuracy of ± 2.1 per cent (that is, 5000 cells counted in 10 seconds for a 5 M count). Leukocyte counts can also be performed in ten seconds with an accuracy of ± 9 per cent for a single count (500 cells counted in a 5000 cu.cm. count).