Incubation time, effect

Under certain conditions hydrogen cyanide can polymerize to black soHd compounds, eg, hydrogen cyanide homopolymer [26746-21-4] (1) and hydrogen cyanide tetramer [27027-02-2], C H N (2). There is usually an incubation period before rapid onset of polymer formation. Temperature has an inverse logarithmic effect on the incubation time. Acid stabilizers such as sulfuric and phosphoric acids prevent polymerization. The presence of water reduces the incubation period. 

Davis KER, SJ Joseph, PH Janssen (2005) Effects of growth medium, imoculum size, and incubation time on culturability and isolation of soil bacteria. ZlppZ Environ Microbiol 71 826-835. 

Sajwan K.S., Lindsay W.L. Effect of redox, zinc fertilization and incubation time on DTPA-extractable zinc, iron and manganese. Commun Soil Sci PlantAnal 1988 19 1-11. 

Kinetics of fMet-tRNA binding to 30S ribosomal subunit Inhibition of ribosomal binding of fMet-tRNA by an antibiotic may reduce the level of initiation complex formed at equilibrium. However, if the effect of the inhibitor consists mainly of slowing down the binding reaction, its effect may appear less dramatic after a relatively long incubation time. For this... 

Figure 15.8 (a) Time course of the activity restoration of formalin-treated RNase A during incubation at 50°C (0-2h) and 65°C (2-4h) in TAE buffer, pH 7.0. (b) Time course of the activity restoration of formalin-treated RNase A during incubation at 65°C in TAE buffers of various pH values. All RNase A preparations were freed of excess formaldehyde by dialysis prior to the assay. The RNase A activity was determined with a colorimetric assay using cytidine 2,3,-cyclophosphate as the substrate as described by Crook et al.54 Note that the slopes of the curves decrease with incubation time at 65°C, which is near the denaturation temperature of native RNase A. This loss of activity is likely due to the competing effect of protein denaturation of the recovered RNaseA at this temperature. See Rait et al.10 for details. 

Recently, Silva et al. have compared several techniques that have been applied to colonial marine invertebrates [13]. Catalan et al. [37] developed a technique in which sponges maintained in aquaria are attached to a plastic plaque. On the plaque, the sponge can be transferred, first to a smaller, aerated, vessel for treatment with an ethanolic or ethereal solution of the desired precursor. Then, after an incorporation period for uptake of the precursor, the sponge is returned to the sea, where metabolism is allowed to proceed in the animal s natural habitat. Silva et al. [13] found that optimal incubation time depended on the sponge, but generally was 20 to 90 days. These authors also reported on the effectiveness of lipophilic compared to hydrophilic precursors the former were taken up and metabolized more efficiently in sponges than hydrophilic ones. 

Fig. 7.2 Effect of fullerene on the surfaces (FoS) (10pg/cm2 of C60) on the fluorescence of 2, 7 -dichlorofluorescein in the presence of different concentrations of H202. (Incubation time -lOmin, - 20min, - 30min 1, 2, 3 - concentration of H202 97, 194, and 970 pM). p < 0.05 ...

Figure 5. Effect of incubation time on the carp liver microsomal mfo activity (NADPH 2 mg/mL, pH 7.4 incubated at 25° C. Microsomal protein concentration...

Figure 4. Effect of incubation time on aldrin epoxidation by midge homogenate...

Smart et al. discovered that indomethacin also blocks caveolae uptake and suggest arachidonate accumulation as a potential inhibitor (66). Indomethacin is described as inhibiting both the internalization of caveolae and the return of plasmalemma vesicles after an incubation time of 30 minutes in the presence of 400 pM in MA104 cells (rhesus monkey kidney cells). The effects are rapidly reversible after removing the drug (66). 

The macrolide antibiotic bafilomycin Al and concanamycin A are specific inhibitors of vacuolar-type H(- -)-ATPase, which prevents the acidification of endosomes and lysosomes and increases the intralysosomal pH from about 5.1-5.5 to about 6.3 (61,84-87). Bafilomycin Al is applied in concentrations ranging from 25-1000 nM and is incubated for 30 to 60 minutes in the presence or absence of serum. We observed maximal effects in COS-7 and HUVEC with concentrations of 100-200 nM and an incubation time of 60 minutes. 

LysoTracker and LysoSensor probes Several commercially available weakly basic amines can be used to stain lysosomes. They selectively accumulate in acidic organelles when applied in very low concentrations (50 nM) and directly before imaging. For live cell imaging, keep in mind that lysosomal probes can exhibit an alkalinizing effect on the lysosomes, such that longer incubation time can induce an increase in lysosomal pH (129). 

Trypsin treatment is described to remove cell-associated lipids after treatment with 0.25% trypsin for a few minutes (better effects are seen with increased incubation time and phosphatidylcholine concentration) (149). 

It is important to know that the use of the different inhibitors has to be evaluated for each cell type, regarding applied concentrations and incubation times. Concentrations that are too high might show toxic effects and might mimic results seen with reduced uptake. Therefore, all experiments need to be accompanied by viability assays. 

To study the effect of pH and temperature, 0.25 ml of the lignin peroxidase diluted with water was mixed with 0.75 ml of buffer, pH 3.0 - 7.0 and incubated at temperatures of30- 70°C. The protein concentration of the incubation mixture was 50 ig/ml. After various incubation times (0 - 27 h) the inactivation was stopped by adding 9 ml of cold 0.33 M tartrate buffer, pH 3.0. 

To study the effect of hydrogen peroxide, the lignin peroxidase was incubated in buffer, either pH 3.0 or 5.0, at the temperature of either 0°C or 10°C. Protein concentration was 30/i,g/ml and the concentration of H2O2 was 0.2 -11.6 mM. The incubation time varied between 0 and 295 min. After incubation 0.4 ml of the enzyme sample was pipetted directly into the activity assay mixture. 

To study the effect of veratryl alcohol, purified lignin peroxidase or unfractionated enzyme preparation was incubated with buffer, pH 3.0 or 5.0. The concentration of veratryl alcohol in the incubation mixture was 0, 10 or 100 mM. Incubation times were 38 days at 20°C and 40 days at 4°C. The protein concentration of purified enzyme was 80/tg/ml and of unfractionated preparation 180 tg/ml. The incubation mixtures were sterile filtered to prevent microbial growth. 

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