5 tube balancing argument

Paul N Hengen pnh at ncifcrf.gov
Wed Oct 9 13:02:14 EST 1996


John Dixon (jpcd0 at mole.bio.cam.ac.uk) wrote:

> Some one here was doing 5 minipreps (equal volume) and was loading a 12
> hole microcentrifuge, when he found that the balance tubes had been
> cleared away. He was about to fill another sixth tube to balance 3
> opposite 3, when I said that you can balance five anyway. This started a
> massive debate, which has now come down to three positions. 
> 
> I reckoned that if you put three tubes in, in a triangle ie in holes 1,5,9
> these are balanced. Then you can balance the two others opposite each
> other in holes 2 and 8.
> 
> One guy maintains that this is not balanced at all, on the grounds that
> you can split the fuge into two halves where one half has two tubes and
> the other has three, therefore it must be unbalanced. I am not convinced. 

You are right! It is balanced. If you draw a plane through the three tubes,
splitting one in half, it is perfectly symmetical.  If you want to give me a
beer for this, I'll take any Octoberfest you got.



More information about the Methods mailing list