The pH of the 10X solution can be slightly different from the pH of the 1X solution (but not usually as big as what you are seeing, I think). So you should check the pH of your 1X solution and adjust accordingly.
When I make PBS 10X stock, the pH is often wrong and I simply adjust it with 5M NaOH. Maybe your calculation did not take into account the pH of the water (usually ~5 or 6, definitely not 7)? Hope that helps, Irit On Jan 3, 2012, at 12:08 PM, Hiranya Roychowdhury wrote: > Since you say you have few questions, I am assuming that you are quite > certain about your composition. PBS stands for "Phosphate buffered saline" > so it is NaCl, not KCl. Usually we use Na-salts for the phosphate > combination. Potassium phosphate and -biphosphate may be used, but for all > practical purposes it is Na- that is preferred since lot of compounds do not > go well with K+ > > > Hiranya S. Roychowdhury, Ph.D. > Associate Professor > Health & Public Services > NMSU-Dona Ana Community College > 575 527 7725 (office) > > ________________________________________ > From: [email protected] > [[email protected]] on behalf of sudheer sangeetham > [[email protected]] > Sent: Tuesday, January 03, 2012 9:52 AM > To: [email protected] > Subject: 10X PBS > > Hi People > > I have few doubts regarding phosphte buffer saline (PBS). Recently I found > one article related to my work, in that they used PBS ( Nacl/iP ) pH-7.4. > Nacl/iP does it mean, it should contain Na2HP04 and NaH2PO4 and Nacl but > not KCl, am I right? > > I have prepared the buffer like this > > NaH2PO4 ( 0.038M) > Na2HPO4.2H20 ( 0.162M) > NaCl (1.5 M ) but when i check the pH it was showing 6.4, is it correct? > did I do any mistake.... > > Could any one please tell me did i do any mistake? > > Thank you in advance > > -- > Sudheer Babu.S > Ph.D student > Institute of Biochemistry > Biological Research Center > Szeged,Hungary. > _______________________________________________ > Methods mailing list > [email protected] > http://www.bio.net/biomail/listinfo/methods > > > > _______________________________________________ > Methods mailing list > [email protected] > http://www.bio.net/biomail/listinfo/methods _______________________________________________ Methods mailing list [email protected] http://www.bio.net/biomail/listinfo/methods
