[rvmarsha6]

I am a temporary employee with a lab right now and I was given some solutions to make up and I was looking for some help on how to prepare the solutions.
1) Fresh HEPES/saline, ph 7.5…. 1 Liter and it needs to be 150 mM
2) Formalin in HEPES/saline at 4°….. 1 Liter

Then I need to mix reagents [2.5 mM CaCl2, 1.25 mM MgCl2, 150mM NaCl, 10 mM HEPES, pH 7.5] 100 mL

If someone could please help me figure out how to make these reagents.  Thanks so much!

[Borek]

http://www.chembuddy.com/?left=CASC&right=solution_preparation

[Babcock_Hall]

With respect to 1), you said "it needs to be 150 mM."  Do you mean that NaCl needs to be 150 mM, or do you mean that HEPES needs to be 150 mM?  I suspect that you mean the former, but then the question becomes what concentration of HEPES you need.

With respect to HEPES, this substance is a buffer at pH 7.5 but is typically sold as a free acid.  Therefore, you will need to add a base to obtain the correct pH.