Question

In a research lab, you will not always be given a protocol with the solutions you will need explicitly described. Often researchers have to adapt to the information that is provided in a published paper in order to make a solution. For the following questions, assume you have been given the following information: 4X TGB Tris-Glycine Buffer) pH83 Tris Glycine 250mM SDS 25mM 0.1% 3) How many milligrams of SDS will you add when making 500mL of 4X TGB? (FW of SDS is 288.38)? (2pts) 4) If you were to make a 1X working solution of TGB, at what concentration will each component be? (2pts) Tris-base Glycine SDS Using your 500mL solution of 4X TGB, show your calculations for making 25mL of 1x TGB. (2pts) 5)

Answer 1

• SDS =0.1%

in 500ml of the 4X TGB

0.1% of 500 ml = 0.5 ml or 500 mg of SDS.

• in order to make 1x from 4x buffer components,

tris base =25mM/4= 6.25mM

glycine= 250mM/4= 62.5mM

SDS= 0.1% of 500 ml= 500mg /4 =125 mg

Mix all the components and make up the volume.

• 4x TGB

Final volume= 25ml (0.025 L)

Final conc.= 1X

Using the formula, C1V1=C2V2,

4X V1= 1X 0.025L

V1= 0.00625 or 6.25 ml

Take 6.25 ml of 4x TGB and dilute it to 25ml of 1X TGB buffer.