GLYCYLGLYCINE BUFFERS 



pH 7.6 - 9.0 



Reference: Determined experimentally in M.B.L. Chemical Room by 

 J. D. Ostrow and J. B. Russell, 1951. Data available 

 on request. 



Stock Solution : 0.500M Glycy Iglycine 



Weigh accurately 33.030 g. of glycylglycine into a 500 ml. volu- 

 metric flask and dilute to the mark with distilled water. Use high purity 

 chemical directly from a bottle opened and kept in the dry room. 



Buffers : 



To make 250 ml. of O.IM buffer pipette 50 ml. of the 0.500M stock 



solution into a 250 ml. volumetric flask. Add the volume of l.OOON 



NaOH indicated in the table below, and dilute to the mark with distilled 

 water . 



Note: A charge will be made for all glycylglycine buffers due to the 

 expense of this chemical. 



BORATE -KCl -NaOH BUFFERS 



pH 7.8 - 10.0 



Reference: Clark and Lubs; J. Biol. Chem. _25_ 479 (1916) 



Stock Solution : A mixture of 0.500M Boric Acid H3BO3 and 0.500M 

 Potassium Chloride KCl 



Weigh out 31.0120 g. Boric Acid and 37.280 g. of KCl and dissolve in 

 enough distilled water to make 1 liter of solution. Use Merck's Reagent 

 grade chemicals. The solid may be weighed directly from the bottle, with- 

 out previous drying, if freshly opened and kept in the dry room. For 

 better accuracy, however, the KCl should be dried at 120 C in an oven for 

 four hours, and the Boric Acid dried in thin layers over CaCl2in a desic- 

 cator. Under no circumstances should the Boric Acid be heated above 50 C, 

 or it loses water of constitution forming metaboric acid HBO2. 



Buffers : 



To make 1 liter of 0.0 5M buffer, pipette 100.0 ml. of the . 5M stock 

 solution into a 1 liter volumetric flask, add the volume of l.OOON NaOH 

 specified below, and dilute to the mark with distilled water. 



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