Protocol Online logo
Top : New Forum Archives (2009-): : Molecular Biology

SB buffer recipe. - (Oct/07/2012 )

Is this recipe for SB buffer correct? i found it online. If not, can you give me the correct recipe please?


50x Stock:

20 g NaOH
pH to 8.0 with approx 120 g H3BO3 (boric acid powder)
bring to 1 L with dH2O

NOTE: This stock will precipitate over time, requiring heat to re-dissolve crystallized salts before dilution.

1x Working Buffer:

20 ml of 50x stock
980 ml dH2O

NOTE: The pH of the working solution will be higher than that of the 50x stock
NOTE: Do not re-use 1x solution for more than a day or it will go fuzzy. Really.

Translated to concentrations:

50x Stock: 500 mM NaOH, pHed to 8.0 w/ H3BO3
1x Working buffer: 10 mM NaOH, pHed to 8.5 w/ H3BO3

Just removed your duplicated post bits. Bob

-Mad Researcher-

Those look correct to me.

I re-use SB several times, sometimes even over a month or so I will use the same buffer. find it slows down after about 5x reuse.


I like the SB buffer and i have replaced my TBE buffer with SB buffer. It was quite fast :-)

-Mad Researcher-

What voltage do you prefer while using SB buffer and for how much time?

-Mad Researcher-

Depends on the size of the product I am looking for. Typical PCR of 500 ish bp, and I would go 300 V for 6 -10 min.


I have 300 bp products and i run it at 150 V for 40 mts.
I am planning to increase the voltage to 250 V and reduce the time to 20 mts.

-Mad Researcher-