Garlic root tips

Does anyone have a tried and trusted method for looking at cell division in garlic root tips? We currently use toluidine blue as a stain and it’s a bit hit and miss whether we see anything of note. Does anyone use a different stain?
Thanks
 
Does anyone have a tried and trusted method for looking at cell division in garlic root tips? We currently use toluidine blue as a stain and it’s a bit hit and miss whether we see anything of note. Does anyone use a different stain?
Thanks
We have done it with 6th form using acetic orcein, and GCSE with Toluidine blue. Have you seen the guidance on CLEAPSS , we have used that method with the Toluidine Blue and it works well. Is your garlic tips around 1cm in length when you cut them? I think if your doing it at GCSE they do have a tendency to overstain.
 

Peter Sigsworth

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Does anyone have a tried and trusted method for looking at cell division in garlic root tips? We currently use toluidine blue as a stain and it’s a bit hit and miss whether we see anything of note. Does anyone use a different stain?
Thanks
staining is usually not a problem - it's finding dividing cells that is the difficulty - lots of patience required and looking in the right place - square shaped small largest nuclei near the very tip. I have a set of prepared bought slides which I default to if they can't find any dividing - expensive but worth it as they can be used indefinitely if looked after.

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We use the cleaps method with warm 1M HCl, I pre soak in the acid and they can then just take their root tip and stain it, we have had problems with them squashing the wrong end before.

Some teachers don't seem to know what the squash bit means.
 
SAPS have a useful guide for this including a short video, the important bit is about washing the excess stain away, if you don't have an oil immersion lens to view the slides a 20 times eye piece will do. The age of the roots is quite important 3 days seems to work best.
 
Good question. Surely the tip is the end that is always growing so age shouldn’t matter, or does it?
We've let it grow for quite a bit (a week). The slides didn't show a lot of cells dividing. This could be because of their method but it made me think that doing it with roots that have grown for ~3 days are better
 
The roots are best at 1-2cm length max. I think even in CLEAPPS it says longer but I never use longer. We always get really good results with Toluidine. We always also use Acetic alcohol to stop further division so you are effectively "freezing the moment". IO have read some methods who say you don't have to do this stage but we always do and we always get results. The only problem we ever have is that the tip isn't broken up enough by the students. They really have to mash it with a mounted needle and then place the coverslip on and "squash"
 

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