Ph probe

Manufactured by Mettler Toledo

Sourced in Switzerland

The PH probe is a laboratory instrument used to measure the acidity or basicity of a liquid solution. It consists of a glass electrode that is immersed in the solution, and it provides a numerical reading of the pH value.

Automatically generated - may contain errors

Lab products found in correlation

Do probe, by Mettler Toledo (2 mentions) Wpa co8000 cell density meter, by Harvard Bioscience (1 mentions) Dasgip parallel bioreactor system, by Eppendorf (1 mentions) Bioflo 2000, by Eppendorf (1 mentions) Trumac cns analyzer, by Leco (1 mentions)

12 protocols using ph probe

Cultivation of iPSCs in Stirred Tank Bioreactors

Check if the same lab product or an alternative is used in the 5 most similar protocols

BioBLU 3c stirred tank bioreactors (Eppendorf) and 125 ml spinner flasks (Corning) were used in this study. The BioBlu 3c was equipped with dissolved oxygen (DO) probe (Mettler Toledo) and a pH probe (Mettler Toledo). The pH probe was calibrated using a two‐point calibration method with standard pH solutions. For the DO probe calibration, vessels were filled with RPMI‐1640 medium (1500 ml) and aerated with air and 5% CO₂ by headspace gassing under the process conditions (i.e., 68 rpm agitation, 37°C) for at least 6 hr. After stable DO values were observed, a slope calibration was performed. The basal RPMI‐1640 medium was removed after DO calibration, and iPSCs were inoculated at 1.0 × 10⁶ cells/ml in 1500 ml of L7 medium supplemented with 10 μM Y‐27632 (referred to as Day 3). The BioBLU 3c was agitated at 68 rpm from Day 3 to 0. Also from Day 2 to 0 the medium was exchanged every day in the bioreactor by removing 50% of the supernatant and adding in the same amount of fresh L7 medium into the bioreactor.
The spinner flask was inoculated at 1.0 × 10⁶ cells/ml in 100 ml of L7 medium supplemented with 10 μM Y‐27632. The spinner flask was placed on a magnetic stir plate agitated at 70 rpm in a humidified incubator operating at 37°C and 5% CO₂. From Day 2 to 0, 50% of the spinner flask supernatant was removed every day and replaced with 100 ml of fresh L7 medium.

Shafa M., Panchalingam K.M., Walsh T., Richardson T, & Baghbaderani B.A. (2019). Computational fluid dynamics modeling, a novel, and effective approach for developing scalable cell therapy manufacturing processes. Biotechnology and Bioengineering, 116(12), 3228-3241.

+ Open protocol

+ Expand

Parallel Bioreactor Cultivation of Yeast

Check if the same lab product or an alternative is used in the 5 most similar protocols

All cultivations were carried out in a DASGIP Parallel Bioreactor System (Eppendorf AG) with four parallel bioreactors and a maximum working volume of 1.2 L. pH was monitored with a pH probe (Mettler‐Toledo) and adjusted to pH 5.5 by the automated addition of 5 M NaOH or 1 M H₂PO₄. The dissolved oxygen concentration was monitored by a VisiFerm DO 120 probe (Hamilton Company) and was controlled at 50% throughout the cultivation by adjusting the gassing rate of pressurized air and the stirrer speed. To reduce foam formation, 5% (wt/vol) Struktol (SB 2121; Schiller+Seilacher GmbH) were added dropwise whenever necessary. All cultivations were performed at 30°C.
For preculture, 100 ml YPD was inoculated with a single colony and incubated overnight on a shaker at 180 rpm and 30°C. Cells were harvested and washed once with sterile deionized water. The cell density was determined with a photometer (Biochrom WPA CO8000 Cell Density Meter) at 600 nm and the cells were used for inoculation of 500 ml cultivation medium with an OD₆₀₀ of 1. All cultivations were performed in triplicates.

Erian A.M., Egermeier M., Marx H, & Sauer M. (2022). Insights into the glycerol transport of Yarrowia lipolytica. Yeast (Chichester, England), 39(5), 323-336.

+ Open protocol

+ Expand

Ion Chromatography Analysis of Nutrient Uptake

Check if the same lab product or an alternative is used in the 5 most similar protocols

Ion chromatography (IC) was undertaken to analyze the nutrient uptake of C. sorokiniana in relation to reduction of nitrate, phosphate and sulfate levels. The samples were run on a KS-1100 IC instrument (Dionex, Thermo Fisher Scientific, Hemel Hempstead, UK), using an AS23 4 × 250 mm carbonate eluent anion-exchange column (Dionex). Anion mode analysis was carried out according to the manufacturer’s recommendations, using a mobile phase of 4.5 mM Na₂CO₃. The flow rate was set at 1 mL min⁻¹, with a total run time of 30 min and temperature held at 30 °C. Cation analysis was undertaken using an IonPac CS16-5 µm (5 × 250 mm) column with 30 mM Methanesulfonic acid as the eluent (Thermo Fisher Scientific, Hemel Hempstead, UK). The flow rate was set at 1 mL·min⁻¹, with a total run time of 25 min and temperature held at 40 °C. Detection of ion peaks in both conditions was undertaken by suppressed conductivity measurements at 25 mA. The spectra were analyzed using a set of standards and software provided by Dionex. The pH of the growth media was monitored over the course of the experiment with a pH probe (Mettler Toledo, Royston, UK).

Lizzul A.M., Lekuona-Amundarain A., Purton S, & Campos L.C. (2018). Characterization of Chlorella sorokiniana, UTEX 1230. Biology, 7(2), 25.

+ Open protocol

+ Expand

Continuous Culture of S. mutans Strains

Cited 1 time

Check if the same lab product or an alternative is used in the 5 most similar protocols

S. mutans strains UA159 and ΔspxA2 were grown under continuous culture conditions using a BioFlo 2000 fermenter (New Brunswick Scientific, Edison, NJ) in TY medium (3% tryptone, 0.1% yeast extract, 0.5% KOH, and 1 mM H₃PO₄) containing 1% glucose, as described previously (Faustoferri et al., 2015 (link)). Cultures were grown at a constant dilution rate of 0.24 h⁻¹ under glucose-limiting (2.3 mM) conditions. Culture pH was continually maintained throughout the experiment via the addition of 2 N KOH and verified by a pH probe (Mettler Toledo, Billerica, MA). Cultures were harvested after 10 generations at steady-state pH 7, followed by addition of excess glucose (20 mM), thereby lowering culture pH. Cultures were similarly harvested at pH 5 after 10 generations at steady-state and stored at −80°C.

Baker J.L., Saputo S., Faustoferri R.C, & Quivey RG J.r. (2020). Streptococcus mutans SpxA2 relays the signal of cell envelope stress from LiaR to effectors that maintain cell wall and membrane homeostasis. Molecular oral microbiology, 35(3), 118-128.

+ Open protocol

+ Expand

Optimizing Oxygen Supply for Batch Fermentation

Check if the same lab product or an alternative is used in the 5 most similar protocols

The oxygen supply was also analysed during batch fermentation in a 10 l bioreactor (Biotech-10JS, Shanghai, China) with 7 l working volume. The DO probe (Mettler-Toledo GmbH, Switzerland) and pH probe (Mettler-Toledo GmbH, Switzerland) measured the DO, pH and temperature, agitation speed were measured online. The pH was adjusted using 2.0 mol l⁻¹ NaOH or 2.0 mol l⁻¹ HCl. The temperature was controlled automatically. Different constant DO 20%, 30%, 40% and 50% in 10 l bioreactors were studied. The three-stage controls were performed as follows: during 0–24 h, the DO was set to 40%; during 24–96 h, the DO was set to 50%; and during 96–240 h, the DO was set to 30%. The four-stage oxygen controls were performed as follows: at Phase I (0–24 h), the DO was set to 40%; at the subsequent culture Phase II (24–96 h), the DO was set to 50%; at Phase III (96–192 h), the DO was set to 30%; at Phase IV (192–240 h), the DO was set to 25%. The DO level (percentage of air saturation) was controlled at constant values (20%, 30%, 40% and 50%) or varying values by cascading different agitation speeds (from 150 up to 500 r.p.m.), and the ventilation was 1 vvm throughout. The other culture conditions were the same as in the above experiments. Three batches were repeated for each experiment.

Bai Y., Zhou P.P., Fan P., Zhu Y.M., Tong Y., Wang H.B, & Yu L.J. (2015). Four-stage dissolved oxygen strategy based on multi-scale analysis for improving spinosad yield by Saccharopolyspora spinosa ATCC49460. Microbial Biotechnology, 8(3), 561-568.

+ Open protocol

+ Expand

Batch Fermentation of Anaerobic Microbes

Check if the same lab product or an alternative is used in the 5 most similar protocols

Batch fermentations were carried out in a bioreactor controlled by an Applikon ADI 1030 bio controller (Applikon Biotechnology). Throughout all fermentation experiments, temperature was maintained at 37 °C and pH at 5.5 by the automatic addition of 3 N NaOH, 1 N HCl using the biocontroler and a pH probe (Mettler Toledo). The bioreactor was initially purged with nitrogen to ensure an anaerobic atmosphere and then inoculated with 6% (v/v) active growing pre-cultures into 1.5 L of synthetic media with the same composition of the pre-culture media (without CaCO₃ to prevent interference with DO measurements). The glucose concentrations for the fermentation studies were comprised between 25 and 35 g/L (138–195 mM), unless otherwise indicated. Other experiments with cellobiose were carried out with the same glucose-equivalent mass concentration. However, controlling residual substrate from pre-culture was not possible. For this reason, the initial substrate concentration was not exactly the same. These variations did not alter the study case and the desired results. Each experience was carried out until complete substrate consumption. All the experiments were performed at least in duplicate.

Buendia-Kandia F., Rondags E., Framboisier X., Mauviel G., Dufour A, & Guedon E. (2018). Diauxic growth of Clostridium acetobutylicum ATCC 824 when grown on mixtures of glucose and cellobiose. AMB Express, 8, 85.

+ Open protocol

+ Expand

Soil Nutrient and Characterization Protocol

Check if the same lab product or an alternative is used in the 5 most similar protocols

Soil was air-dried and passed through a 5 mm sieve to remove large debris and rocks. Soil nitrate (NO₃) and ammonium (NH₄) extractions were performed using 2.0 M KCl [48 ] and analyzed on an AutoAnalyzer 3 (SEAL, UK). Soil pH was measured with a pH probe (Mettler Toledo, USA) using a 1:2 soil to 0.1 M CaCl₂ solution [49 ]. Air-dried, sieved soil was ball-ground (Retsch MM-400, Germany) and 0.25 g of soil was used to determine total N and C. Total C was combusted at 1100°C with a LECO C632 analyzer (LECO, USA) and total N was combusted at 1250°C with the TruMac CNS analyzer (LECO, USA).

Aguiar M., Conway A.J., Bell J.K, & Stewart K.J. (2023). Agroecosystem edge effects on vegetation, soil properties, and the soil microbial community in the Canadian prairie. PLOS ONE, 18(4), e0283832.

+ Open protocol

+ Expand

Measuring pH of Microbial Communities

Cited 1 time

Check if the same lab product or an alternative is used in the 5 most similar protocols

The pH of each community in Fig 4D was measured using a phenol red assay as described previously (Clark et␣al, 2021 (link)). The pH of each supernatant in Fig 4E was measured using a pH probe (Mettler Toledo). The pH of each supernatant was adjusted to the pH of fresh media by adding small volumes of sterile 5 M NaOH and 5 M HCl.

Hromada S., Qian Y., Jacobson T.B., Clark R.L., Watson L., Safdar N., Amador‐Noguez D, & Venturelli O.S. (2021). Negative interactions determine Clostridioides difficile growth in synthetic human gut communities. Molecular Systems Biology, 17(10), e10355.

+ Open protocol

+ Expand

Germ-Free Mice Arginine Diet Study

Check if the same lab product or an alternative is used in the 5 most similar protocols

All germ-free mouse experiments were performed following protocols approved by the University of Wisconsin-Madison Animal Care and Use Committee. Two diets were used in this experiment: regular diet with lower arginine concentration (Chow diet, Purina, LabDiet 5021) and high arginine diet (Envigo, TD.210715). All strains were grown at 37 °C anaerobically in YBHI media (Acumedia, Bacto, and Sigma-Aldrich) for 16hrs. All strains for oral gavage were mixed in equal proportions based on OD600 and transferred on ice prior to oral gavage. We used 8-week old C57BL/6 gnotobiotic male mice (wild-type) fed the specific diets 3 days prior to oral gavage. The mice from the same group (4 mice) were housed in the same biocontainment cages (Allentown Inc.) for the duration of the experiment. Mice were maintained on autoclaved water. Fecal samples were collected every 2–3 days after oral gavage for NGS sequencing and pH measurement. The pH of diluted fecal and cecal samples was calculated by measuring the supernatant of 0.1% (v/v) dilution in molecular grade water using a pH probe (Mettler-Toledo)^{71 (link)}. At the end of the experiment, mice were euthanized, and the cecal contents were collected for NGS sequencing and pH measurement.

Liu Y., Cheng Y.Y., Thompson J., Zhou Z., Vivas E.I., Warren M.F., Rey F.E., Anantharaman K, & Venturelli O.S. (2024). Shaping human gut community assembly and butyrate production by controlling the arginine dihydrolase pathway. bioRxiv.

+ Open protocol

+ Expand

Microbial Bioconversion of Glycerol to 3-HP

Check if the same lab product or an alternative is used in the 5 most similar protocols

Bioreactors of 500-mL total working volume (Global Process Concept, La Rochelle, France) were used with an initial working volume of 200 mL. The bacterial cells obtained from the growth step were diluted in osmosis water to reach a concentration of 21.6 ± 2.3 gCDW•L -1 (2.5 ± 0.3  10 10 cells•mL -1 ) then introduced into the bioreactor. The bioconversion was started by feeding the resting cells with glycerol using a peristaltic pump (Watson Marlow 120U-DV, La Queue Lez Yvelines, France). The concentration of the glycerol solution was defined between 44 and 110 ggly•L -1 , depending on the targeted specific glycerol feeding rate, as defined by the experimental design. Temperature and agitation were controlled at 37 °C and 100 rpm, respectively. The partial pressure of dissolved oxygen (pO2) was measured by an optical dissolved oxygen probe (Hamilton, Bonaduz, Switzerland). The pH was measured using a pH probe (Mettler Toledo, Viroflay, France) and controlled at a value defined by the experimental design by adding NH4OH 1.48 mol•L -1 . The volume variation in the bioreactor was calculated on-line by considering both glycerol and NH4OH addition. Bioconversion was interrupted when no more 3-HP was produced, which was evaluated by the cessation of base consumption and by the concomitant increase in pO2 [6] .

Nguyen T.L., Béal C., Ghorbal S, & Saulou-Bérion C. (2023). Environmental conditions during glycerol bioconversion affect 3-hydroxypropionic acid bioproduction by Limosilactobacillus reuteri DSM 17938. Biotechnology progress, 39(1).

+ Open protocol

+ Expand

About PubCompare

Our mission is to provide scientists with the largest repository of trustworthy protocols and intelligent analytical tools, thereby offering them extensive information to design robust protocols aimed at minimizing the risk of failures.

We believe that the most crucial aspect is to grant scientists access to a wide range of reliable sources and new useful tools that surpass human capabilities.

However, we trust in allowing scientists to determine how to construct their own protocols based on this information, as they are the experts in their field.

Ready to get started?

Revolutionizing how scientists
search and build protocols!