Test tube, sidearm

Tomato cell suspensions in modified Murashige and Skoog medium (12) were assayed for change in cell volume at varying concentrations of polar and nonpolar extracts. Twenty-five ml erlenmeyer flasks (5 reps/treatment) containing 10 ml of sterile medium, tomato cell suspension, and extract were allowed to settle for 20 min in sidearm test tube attachments. Relative height of cell volume fraction to medium was recorded each day for 11 days. Cell suspensions were incubated in the dark at 27 C on an orbital shaker at 125 rpm. The doubling time of control cell suspensions were approximately 2.25 days. 

To prevent clogging of the capillary by the test solution, a flow of mercury should always be started before the capillary is immersed in the solution. At the end of the experiment, the DME is removed and thoroughly rinsed with solvent and distilled water while mercury is still flowing. When the water has evaporated, the mercury reservoir is lowered until the head of mercury above the capillary is below the sidearm. The capillary can be stored dry or in a test tube filled with mercury. 

Figure 115 shows three forms of sublimation apparatus. Note all the similarities. Cold water goes in and down into a cold finger on which the vapors from the crystals condense. The differences are that one is larger and has a ground glass joint. The sidearm test tube with cold-finger condenser is much smaller. To use them,... 

X 150 mm sidearmed test tube) Figure 5.28 Side-arm test tube as a vacuum dryhing apparatus. 

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