Australia's Science Forum

Do you have any stainless steel/nickle plate electrodes you need a broad electrode
I have seen people wrap alfoil over each end of tub and just connect alligator clip either end

Thanks ocker, I'll give that a go. I used 2 powerpacks rather than batteries

I also used the soaked filter paper method

A girl after my own heart!

I did it just with alfoil. Worked well. Make sure you have things that will separate. Red just moves as it has nothing to separate into. Blue and yellow might do the same.

Yes! I use Violet, Green (best) and brown

Ocker wrote:A girl after my own heart!

It's the sporran that does it Ocker!

I've had success!

Used agar made without the bicarb, in a thinner layer, and poured bicarb over the top of the set agar , which was in a thinner layer. Also used plate electrodes of stainless steel. My green seperated quite well after 50 minutes! I'll have to try to get some purple or black, as the other colours didn't seperate - they must be very " pure" primaries.

Ocker, are you able to share your exact procedure for this practical? It sounds interesting.

G'Day Dave, I take it you have mould with comb to create holes in agar gel blocks
Put food dye on filter paper cut thin strips when dried roll into tight coil round Bio mounted needle use tweezers to insert in holes in gel
place in bottom of bath then slowely pour in Bicarb solution to just cover apply 24V
Now it is possible for some dyes to migrate backwards, this means they have a negative charge.
now Curie Have you been peeking?

BTW the red moves the slowest ie largest chain dye

Ocker wrote:G'Day Dave, I take it you have mould with comb to great holes in agar gel blocks
Put food dye on filter paper cut thin strips when dried roll into tight coil round Bio mounted needle use tweezers to insert in holes in gel
place in bottom of bath then slowely pour in Bicarb solution to just cover apply 24V
Now it is possible for some dyes to migrate backwards, this means they have a negative charge.
now Curie Have you been peeking?

Under your sporran?
Not likely!

I found for chromatography that our food colours didn't separate too well using the ordinary filter paper method so I made a mixture of all colours and then condensed it down. I guess you could do the same for this - make your own purples, oranges and greens (and black - just put in everything!) and you know you will get at least 2 colour bands! I am tempted to try this myself

The good thing about doing this on filter paper is you can use pens too. we used black pen and a few other Crayola coloured pens as well as some food colouring. One of the pens had a blue colour that moved backwards.

Artline felt tips are great too