Making Solutions: Recipes

     One of the key lessons in a lab is making solutions. In research labs, there are usually stock solutions, but it is important to learn how to make each of these solutions yourself. This post gives a list of commonly used solutions in a research lab and how to make them. Be sure to label each solution clearly, with its concentration and pH if needed. Also, include the date.

LB Broth

     The following are needed per litre of LB broth: 10g bacto-tryptone, 5g bacto-yeast extract, and 10g NaCl. If you are making more or less than one litre, you will need to calculate the amount of each ingredient needed. Once you have added the dry ingredients to a bottle, add the amount of water needed (1L if making 1L of LB, 250mL if making 250mL of LB, etc.). Then, shake the bottle to mix it thoroughly. Since LB is usually used as a growth media, it needs to be clean. Place foil over that cap of the bottle and use autoclave tape to hold down the foil. When the autoclave is done, the tape will have changed colour, indicating that the substance has been autoclaved. When you are done, tighten the cap and store the LB broth in a -4 degree Celcius fridge.

Tris Base (pH 7.5, 0.1M)

     Use 2,428g of Tris base to make 200mL of the solution. Pour 80mL of nanopure in a flask and add the tris base to the water. Use a stir bar to dissolve all the dry material. Then, calibrate a pH metre and dip it into the solution, right above the stire bar. Add HCl until the pH reaches 7.5. Add nanopure until you reach the 200mL mark, and store at room temperature.

Ampicillin Solution (50mg/mL)

     To make 1mL of ampicillin, use 50mg of ampicillin powder and place it in a 1.7mL centrifuge tube. Then, add 1mL of water and vortex it to mix the solution. Once all the solid is dissolved, filter sterilize the solution through a 0.22um syringe filter on a 1mL syringe. Dispense all of the solution in a new sterile 1.7mL tube. Wrap the tube in foil and place it in a -20 degree freezer for storage.







TGS running buffer (for protein gels)

     Add 80mL water into a beaker and add 1.51g Tris base, 9.4g glycine, and 0.5g SDS. Stir the solution and add nanopure until you reach the 100mL mark. Store at room temperature.