Exponential dilution flask

Figure 8.31 l q ratus for preparing standard mixtures of organic vapors. A, exponential dilution flask B, diffusion tube system. 

Exponential Dilution Flask A )cnown amount of pure coiqwnent or standard mixture is introduced into the vessel, which is stirred for efficient mixing. The vessel is continuously flushed with a steady stream of gas causing the concentration of the vapor to decrease with time. 

Figure 2. Illustration of exponential dilution from an exponential dilution flask.

So we now have the situation illustrated in Figure 3 Here we have a situation analogous to our exponential dilution flask ... 

One of the best methods of determing hnearity of response of any gas analysis system is exponential dilution. It is a simple method to set up and yields a large amount of experimental data over a relatively short period of time. This is especially true in the case of a multi-component mixture. This method employs a mixing flask of fixed volume with two inputs, one for starting gas, one for diluent gas and one exit for the gas mixture. (See Figure 2). 

Prepare a cell suspension in fresh growth medium from a flask of cells in exponential growth and count cells. Dilute cells to density of 104 cells /mL (see Note 1) allowing 30 mL of cell suspension for 3 plates. Transfer the cell suspension to a 10 cm Petri dish and with a multichannel pipet add 100 pL to the central 10 columns of a round bottomed microtitre plate. Add 200 pL of growth medium to the wells in columns 1 and 12. Put plates in a plastic box and incubate in a humidified atmosphere at 37°C while drug solutions are prepared. 

EL coli seed culture from the lyophilized cells was grown in a 250 mL flask with a LB medium (yeast extract, 10 g/L, trypton, 10 g/L, pH 7 adjusted with 1 N NaOH) placed on a rotary shaker (250 rpm). When the flask culture reached exponential growth phase, it was diluted 20 times and inoculated into the reactor. The medium and air flow rates were maintained at 2 mL/h and 100 mL/min, respectively. 

Dilute the overnight culture 1 100 in 50 mL of fresh BHI broth in a 500-mL flask and incubate at 37 °C in an orbital shaker at 200 rpm until the ODgoo reached 0.8 (exponential growth phase). 

Grow mouse myelomas in static flasks or spinner culture and keep growing exponentially in DMEM containing 10% or 20% FCS (dilute to 2-3 x 10 ceUs/ml the day before fusion). 

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