Chemical Forums

Please login or register.

Login with username, password and session length

Sponsored links

Pages: [1]   Go Down

Author Topic: PBS for samples Dilution - ELISA  (Read 308 times)

0 Members and 1 Guest are viewing this topic.

lab2015

  • Regular Member
  • ***
  • Mole Snacks: +0/-0
  • Offline Offline
  • Posts: 12
PBS for samples Dilution - ELISA
« on: December 01, 2016, 05:42:09 AM »

I need to dilute my samples with 0.01 mol/L PBS (pH=7.0 - 7.2)
I have a 10x  PBS :
1x (pH = 7.4±0.1) contains:
11.9 mM Phosphate
137 mM Sodium Chloride
2.7 mM Potassium Chloride

it looks like it has the concentration that I need.

Would you please tell me if this is right? should the diffrence in pH be corrected? I need pH= 7 to 7.2 while the pH here is 7.4±0.1

Many thanks,
Logged

Yggdrasil

  • Retired Staff
  • Sr. Member
  • *
  • Mole Snacks: +478/-21
  • Offline Offline
  • Gender: Male
  • Posts: 3172
  • Physical Biochemist
Re: PBS for samples Dilution - ELISA
« Reply #1 on: December 02, 2016, 05:22:30 AM »

You probably would not have problems using a pH 7.4 buffer versus ph 7.2.
Logged

Babcock_Hall

  • Chemist
  • Sr. Member
  • *
  • Mole Snacks: +168/-11
  • Offline Offline
  • Posts: 2698
Re: PBS for samples Dilution - ELISA
« Reply #2 on: December 02, 2016, 06:03:30 AM »

If you dilute a 10X buffer to 1X, the pH should move somewhat.  One reason is that the change in ionic strength affects the practical pKa value.  Dilution of an acidic buffer increases the pH; basic buffers should behave oppositely.  Both Perrin and Boyd's book and Beynon and Easterby's book mention this effect.  The change in pH upon dilution might be small enough not to worry about, but there is no harm in being aware of it.
Logged

lab2015

  • Regular Member
  • ***
  • Mole Snacks: +0/-0
  • Offline Offline
  • Posts: 12
Re: PBS for samples Dilution - ELISA
« Reply #3 on: December 04, 2016, 10:34:33 PM »

You probably would not have problems using a pH 7.4 buffer versus ph 7.2.

Thank you for your reply
Logged
Pages: [1]   Go Up
 

Mitch Andre Garcia's Chemical Forums 2003-Present.

Page created in 0.069 seconds with 23 queries.