Efficient Buffer Preparation: 500ml MgCl2, Glucose, ATP, and Tris-Cl at pH 7.8

  • Thread starter Thread starter vande060
  • Start date Start date
  • Tags Tags
    Buffer
Click For Summary

Discussion Overview

The discussion revolves around the preparation of a specific reaction buffer containing MgCl2, glucose, ATP, and Tris-Cl at pH 7.8. Participants are addressing calculations related to the concentrations and volumes of stock solutions needed for this buffer preparation, as well as considerations for adjusting the pH of the Tris solution.

Discussion Character

  • Homework-related
  • Mathematical reasoning

Main Points Raised

  • One participant outlines their calculations for the required amounts of MgCl2, glucose, ATP, and Tris-Cl, using the equation C1V1 = C2V2 for concentration calculations.
  • Another participant confirms that C1V1 = C2V2 can be applied to molar concentrations without needing to convert to g/L.
  • There is a suggestion that the participant should prepare a new buffer using the Henderson-Hasselbalch equation for adjusting the pH of the Tris solution.
  • A later reply offers a brief acknowledgment that the calculations appear acceptable but does not provide detailed feedback.

Areas of Agreement / Disagreement

Participants generally agree on the use of the C1V1 = C2V2 equation for concentration calculations, but there is uncertainty regarding the preparation of the Tris buffer and whether a new buffer needs to be made.

Contextual Notes

There are unresolved questions about the necessity of starting over with the Tris components versus using the previously prepared solution, as well as the implications of pH adjustments on the buffer preparation.

Who May Find This Useful

This discussion may be useful for students or researchers involved in buffer preparation in biochemical experiments, particularly those focusing on molarity calculations and pH adjustments in laboratory settings.

vande060
Messages
180
Reaction score
0

Homework Statement


Prepare 500ml of a reaction buffer containing .82% MgCl2, 62.5 mM glucose, 950 ATP, and 100mM Tris -Cl, pH 7.8 Use the stock solutions you have prepared

we had to prepare in previous problems:

500ml 1.75M glucose
25mL 2.5% glucose
2L of 1.8 Tris, pH 8.5


Homework Equations


C1V1 = C2V2
Pka Tris = 8.1
glucose mol mass = 180.16
ATP mol mass = 507.8

------------


The Attempt at a Solution



my calculation for MgCl2:

.82% = .82g/100ml = 8.2g/L
15% = 15g/100ml = 150g/L

C1V1=C2V2

150*x = 8.2*500

x = 28mL stck 15% MgCl2

My calculation for glucose

1.75M glucose = 315g/L
62.5mM = 11.2 g/L

C1V1=C2V2

11.2*500 = 315*x

x = 17.7 ml 1.75M glucose stock

Here is my calculation for ATP

5mM ATP = 3g/L
950nM ATP = .00048g/L

C1V1=C2V2

3*x = .00048*500

x =.08ml of stocK 5mM ATP

My calculation for the Tris I am not sure about, can I use my original pH 8.5 solution the prof asked me to prepare, or do I have to start over with the Tris acid and base components and use henderson H equation? does this all look right so far?
 
Physics news on Phys.org
C1V1 = C2V2 works for molar concentrations as well, you don't have to convert them to g/L.

My guess is you should prepare new buffer from HH equation.
 
Borek said:
C1V1 = C2V2 works for molar concentrations as well, you don't have to convert them to g/L.

My guess is you should prepare new buffer from HH equation.

is the rest of it right?
 
Looks OK, but I just skimmed.
 

Similar threads

Henderson-Hasselbalch buffer calculations - B + A Question
  • · Replies 8 ·
Replies
8
Views
3K
Chemistry review questions-calculations
  • · Replies 4 ·
Replies
4
Views
11K