scholarly journals A GLASS ELECTRODE APPARATUS FOR MEASURING THE pH VALUES OF VERY SMALL VOLUMES OF SOLUTION

1929 ◽  
Vol 12 (6) ◽  
pp. 805-811 ◽  
Author(s):  
D. A. MacInnes ◽  
Malcolm Dole

A glass electrode apparatus is described with which pH measurements can be made with as small volumes as 2 drops (about 0.14 cc.) of solution. Using this apparatus the change of pH of the vacuolar sap of Nitella, due to the penetration of brilliant cresyl blue, has been readily followed. The sap and the dye have been found to poison the usual type of hydrogen electrode.

1923 ◽  
Vol 5 (6) ◽  
pp. 727-740 ◽  
Author(s):  
Marian Irwin

When cells of Nitella are placed in buffer solutions at pH 9, there is a very slow and gradual increase in the pH of the sap from pH 5.6 to 6.4 (when death of the cells takes place). If the living cells are placed in 0.002 per cent dye solutions of brilliant cresyl blue at different pH values (from pH 6.6 to pH 9), it is found that the rate of penetration of the dye, and the final equilibrium attained, increases with increase in pH value, which can be attributed to an increase in the active protein (or other amphoteric electrolyte) in the cell which can combine with the dye.


1926 ◽  
Vol 10 (1) ◽  
pp. 75-102 ◽  
Author(s):  
Marian Irwin

Experiments on the exit of brilliant cresyl blue from the living cells of Nitella, in solutions of varying external pH values containing no dye, confirm the theory that the relation of the dye in the sap to that in the external solution depends on the fact that the dye exists in two forms, one of which (DB) can pass through the protoplasm while the other (DS) passes only slightly. DB increases (by transformation of DS to DB) with an increase in the pH value, and is soluble in substances like chloroform and benzene. DS increases with decrease in pH value and is insoluble (or nearly so) in chloroform and benzene. The rate of exit of the dye increases as the external pH value decreases. This may be explained on the ground that DB as it comes out of the cell is partly changed to DS, the amount transformed increasing as the pH value decreases. The rate of exit of the dye is increased when the pH value of the sap is increased by penetration of NH3.


2003 ◽  
Vol 43 (2) ◽  
pp. 179-187 ◽  
Author(s):  
Elisabeth Rodríguez-González ◽  
Manel López-Bejar ◽  
Dolors Izquierdo ◽  
María-Teresa Paramio

1992 ◽  
Vol 20 (6) ◽  
pp. 454-460 ◽  
Author(s):  
M Lazzaroni ◽  
O Sangaletti ◽  
G Bianchi Porro

A comparison was made of the antisecretory activity of orally administered nizatidine and ranitidine by measuring intragastric pH under basal conditions and during and after pentagastrin stimulation. Intragastric pH values were measured with a bipolar glass electrode in 10 patients with healed duodenal ulcers treated with nizatidine or ranitidine according to a randomized single-blind design. The antisecretory activity of the two drugs was similar during the 4 h of monitoring following drug administration. Nizatidine, however, showed a more rapid inhibitory action than ranitidine, producing a significantly greater increase in pH with respect to basal values during pentagastrin infusion. In the period following infusion the pH values observed with ranitidine were higher than with nizatidine, but not significantly so. Under these experimental conditions, therefore, the antisecretory activity of nizatidine was shown to be more rapid than that of ranitidine and equally effective.


2016 ◽  
Vol 81 (12) ◽  
pp. 1407-1414 ◽  
Author(s):  
Dragan Veselinovic ◽  
Zoran Velikic

Measurements of pH values of buffer solutions (pH 4.0, 7.0 and 10.0) and distilled water have been performed with a glass electrode in electromagnetic field at the frequency interval of 10 MHz to 200 MHz and the output power of dispersed and reflected electromagnetic radiation of 0.01 W to 3 W. In all the cases, there occurred a reduction of pH values, i.e. a "recorded pH value" was obtained. The reduction appears within the applied frequency interval reaching extreme values at specific frequencies. The reduction of the pH values increases with the radiation power and depend of the solution buffer capacity. The effect of electromagnetic field on pH value change is exerted dominantly through the influence on glass electrodes.


2021 ◽  
Vol 14 (2) ◽  
pp. 452-456
Author(s):  
Mohamed Fathi ◽  
Amr F. Elkarmoty

Aim: Several factors had been concerned with the developmental competence of the sheep oocyte. This study aims to investigate the effect of adding growth factors (insulin-like growth factor 1 [IGF-1] and epidermal growth factor [EGF]) in the maturation medium of ewe oocytes selected based on brilliant cresyl blue (BCB) screening on in vitro maturation (IVM), fertilization, and pre-implantation embryo development. Materials and Methods: Cumulus-oocyte complexes (COCs) were obtained from the ovaries of slaughtered ewes by either aspiration or slicing techniques. COCs were in vitro matured in a medium containing IGF-1 and EGF (control group). For BCB screening, oocytes were stained and divided into BCB+ oocytes that matured in the same maturation conditions without adding growth factors (Group 2) or in the presence of growth factors (Group 3), and BCB– oocytes that matured in medium without growth factors (Group 4) or with growth factors (Group 5). Results: The supplementation of the maturation medium with growth factors during IVM of (BCB+) oocytes resulted in a significant increase in nuclear maturation rate (90.9%), fertilization rate (75.6%), and embryo developmental rates (60.0%, 46.7%, and 33.3% for cleavage, morula, and blastocyst, respectively). Conclusion: Culturing BCB+ oocytes in a maturation medium containing both EGF and IGF-1 showed a significant improvement in nuclear maturation, fertilization, and pre-implantation embryo development in vitro.


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