24 CHEMICAL COMPONENTS OF CELLS (2) 



Exercise IV 



EQUIPMENT 



Per student 



test-tube rack 



400-ml (or 250-ml) beaker 



bunsen burner 



ring 



wire gauze 



2 stirring rods 



7 test tubes (16 X 150 mm) 



2 quart jars with tops 



dropping pipet 



Per 8 students 



matches 



capillary tubing 



2 needles and white thread 



2 small test tubes of 10~'^ Af solutions of each of the 

 following: alanine, aspartic acid, histidine, lysine, 

 and methionine 



bottle of Benedict solution (250 ml) prepared as 



follows: 



Dissolve 173.0 of sodium citrate and 100 gm of 



sodium carbonate in 800 ml of water by heating. 



Filter if necessary. Dissolve 17.3 gm of copper sul- 

 fate in 100 ml of water. Add it slowly to the citrate- 

 carbonate solution, with constant stirring. Make up 

 to 1 liter with water. 



2 small test tubes of 1.0 mg/ml solutions of each of 

 the following: adenine, cytosine, uracil, and 1 of a 

 mixture of the three 



bottle of Lugol's solution (250 ml) prepared as fol- 

 lows: 



Dissolve 1 gm of iodine (I2) and 2 gm of potassium 

 iodide (KI) in 20 ml of water. Add this to 980 ml 

 of aqueous solution containing 25% KCI (w/v). 



Per 30 students 



0.5% ninhydrin in acetone (1 liter) 

 formic acid, isopropanol, water (10:70:20) (2 liters) 

 acetic acid, butanol, water (15:60:25) (2 liters) 

 12-cm- Whatman No. 1 filter paper (300 sheets) 

 wax paper (2 rolls) 



Per laboratory 



ultraviolet germicidal lamp and safety glasses 



warm oven 



water baths at 100°C 



