5 tube balancing argument

[Edgar Valencia]

I think If your tubes create a perfect equilateral (spelling?) triangle, 
is ok. About the pentagon I also think is not in perfect balance, but I 
should confess I have done it

                          Edgar Valencia Morales
                    Departamento de Genetica Molecular
                               CIFN - UNAM
                                  MEXICO
                        e-mail edgar at cifn.unam.mx


On 9 Oct 1996, John Dixon wrote:

> At the risk of starting a bandwidth hungry inconsequential argument
> (judging by the amount of time spent in our lab jibbering about this), I
> would like to ask a simple question:-
> 
> 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. 
> 
> Then another guy said that he balances five by putting them in as near a
> pentagonal position as he can ie 1, 3, 5, 8, 10. I dont think this is OK
> because you cannot remove a balanced pair to leave a balanced three,
> although I doubt it does much harm.
> 
> Are there any centrifuge balancing experts out there?
> 
> Apologies for innapropriate use of the newsgroup, but maybe some of us are
> trashing our fuges and more importantly several pints are resting on this!
> 
> -- 
> John Dixon                                        Lab 44 (1223) 334131
> Wellcome/CRC Institute                            Fax 44 (1223) 334134
> Department of Genetics
> Cambridge University    
> United Kingdom                           e-m: jpcd0 at mole.bio.cam.ac.uk
> 
>