Protocol Online logo
Top : Forum Archives: : Molecular Biology

'Blue loading buffer' - (Oct/20/2005 )

i would like to know the important of 'blue loading buffer' and the content of this blue loading buffer to the experiment of electroforesis agarose gel.....someone please answer me....thanks a lot....

-shilashah-

blue so you can see
glycerol ~ 30% so it go inside the well

-Gincel-

xylene cyanol and bromophenol blue, two components of the loading dye that allows to estimate relative migration. For ex : in a 1%agarose, BPB moves as 300pb and XC moves as 2kpb.
fred

-fred_33-

I have a question! How to calculate the size BPB and XC move as in different concentration agarose? For ex: What's the size BPB and XC move as in a 0.8% agarose?

-htding-

QUOTE (htding @ Oct 20 2005, 11:08 AM)
I have a question! How to calculate the size BPB and XC move as in different concentration agarose? For ex: What's the size BPB and XC move as in a 0.8% agarose?



i use bromofenol blue and sukrose for 0,8 % agarose.
i get that recipe from sambrock
thank you,
tomoe

-tomoe-

QUOTE
How to calculate the size BPB and XC move as in different concentration agarose? For ex: What's the size BPB and XC move as in a 0.8% agarose?

hi
i get in the maniatis rates, but here you can find additional information
Here you are :
Agarose %...... XC.............BBP
0.5–1.5......... 4–5 Kb ...400–500 bp
2.0–3.0......... 750 bp ......100 bp
4.0–5.0.........125 bp........ 25 bp




you'll get relative migration in acylamide gels here


fred

-fred_33-

Our lab switched several years ago to an Orange G-based loading buffer/tracking dye (at 6X: Orange G (0.25% w/v) in ficoll (15% w/v), glycerol (30% w/v), or sucrose (40% w/v) in 1X electrophoresis buffer).

The Orange G band runs at ~50 bp, and does not show up on photos taken under UV light (like bands of xylene cyanol/bromophenol blue do). It's convenient as it stays out of the way, and is especially useful if you do a lot of small DNA electrophoresis (like small PCR products, for example).

We use this loading buffer exclusively now...

-HomeBrew-