Australia's Science Forum

Dear All - Thanks heaps for your tips on attaching gold leaf to electroscopes, much appreciated. I am seeking your comments on the movement of material in xylem and phloem using celery. Do you have much success when making a coss section slide with the dyed clelery stalk? I guess it is a technique that takes some practise? We don't seem to be able to see too much under the scope that makes any sense! Any comments? Do you all use the Celery? Is there some other plant material that is better? Your comments would be appreciated. Cheers. Jude

I have never done that prac (am newish to labbie land) but my thoughts would be you are not cutting the section thin enough? How are you cutting the cross section? do you have a hand microtome?

We use single sided razers and the results are excelent. Students need a bit of practice, but the resulting cuts are thin enough.
Lada

You are staining with Eosin? Thin section with razor blade is best.

Hi there,

I am just wondering why the lab assistants are cutting thru the celery. Isnt that the teachers job? I just buy the celery and leave it in the tub with the scalpels for the teacher??? I would have thought the teacher and the kids do the cutting.

I have always been a firm believer that the students need to make their own pracs.work!!.Therefore they do the slicing, afterall they are seniors and should know the safety rules. I soak the celery in red food dye overnight and the teacher and kids do the rest!!!!! This prac.has always worked for us!!!!!
Cheers
Mother

I just stand half the celery in water with a good dose of food colouring (blue or red), the other half is left in uncoloured water. It helps the cut the stems off at the base just before you put them in water. It's best left overnight. If you're short of time you can help it along by putting it in a drafty area which will cause the leaves to lose water, thereby sucking more up the stem. By the time it goes to the class I can see the colour in the leaves.

I never cut the stems, the students are given scalpels and chopping boards. The prac here is for them to learn how to make a slide, so it would be pointless if I did the work for them.

Thank you one and all. Your comments have been most interesting, liked the tip about using the draft to pull more stain up the stem, thanks Merilyn. I am not making the slides for the students, the teacher seemed to think it might be the plant matter we have been using that was at fault. I was of the opinion as all of you are, that it is the student technique that needs improving. One is unlikely to get it on the first try! We have the microtome so it is just a matter of practice, practice, practice. Thanks heaps. Jude

Make sure that your celery has enough leaves to allow transpiration, to draw water up. Can use red food colouring if you have no eosin.
Place the celeryin the dye water out in the lab, with cutting boards. scalpels or razors or hand microtomes. the teachers and studetns are to cut it themselves