Australia's Science Forum

Dear All - Does anyone have a recipe for the enzyme trypsin - Can't find anything in the "Laboratory". I only have a very small amount approx 1g, so am hoping I don't need anymore than that. Your input would be appreciated. Cheers. Judy.

We are extremely lucky we have a classroom section in the middle of the labs, with carpet, desks and chairs and around the perimeter of the room we have work benches complete with sinks, gas taps and cupboards for storage. All students doing pracs must stand, that is one of the lab rules. If the stu...

Welcome back!! hope you all had a good break and are now ready to do it all again!!! Many Thanks to all who helped me out with the problem of condensation on agar plates - have since made a new batch following ALL your suggestions and had great success. Once again Many thanks. Judy.

Dear All - I have been reading with interest your comments on RA's!! Do you leave the responsibility of the RA's entirely to the teachers? I also have the last minute, no time to do the paperwork staff!! They all know they have to be done but unless I hand them a blank RA form it may get done or it ...

Dear All (Louise, Lorrae, Helen, Kate, Liz and Rainbow-sky) - Thank you so much for your suggestions - of course I have been doing all the wrong things - pouring too hot, not warming petri dishes, not stacking plates etc.etc. I will use ALL your suggestions next time I'm preparing agar plates. Once ...

Dear All - Having a lot of trouble with condensation falling onto the lid of the petri dish containing the Agar (I incubate the plates upside down the idea being to prevent the condensation falling onto the agar) But I seem to have an awful lot of condensation - is there any way I can prevent this o...

Dear Mother - Just logged-in after a few hectic days - so just catching up with the latest!!! We had some older type Voltameters and unfortunately the electrodes broke so we purchased a new Voltameter from Q Stores. The electrodes were made in such a way that they filled almost the entire glass cyli...

Dear Robbie - Thank you very much for your help re the peptone broth
and also the protein solutions, I too have the same problem - so I will be changing to the gelatin solution as suggested. Once again thanks a lot!! Cheers Judy.

Dear All - I am having trouble with the peptone broth that did NOT become contaminated with microorganisms as expected during Pasteur's experiment. Must admit the peptone I am using has been in the lab for 25 years (That's how long I've been here) God knows how many years before that!! So maybe it's...

Dear Kate - we had the same problem - we were unable to light the LED using lemon power , however if you put lots off lemons in series (Maybe 8 or 10) it is possible to light the LED (we did it!!!). Hope this helps. Judygee

Thank you to Dianne and Kim for your suggestions, I wasn't talking about sulphur in particular but a build up, over the weeks, of a number of different compounds. I put them over the heat --- (it took a while) but I now have clean deflagrating spoons. Thank you both. Cheers. Judy.

Hello everyone - seeking your experience cleaning deflagrating spoons!! Ours usually end up in a horrible mess with built-up residue because they haven't been cleaned properly between pracs. Any suggestions? Judygee.

Dear Helen - Our Vertex is a multistage purification system - Water passes through a cartridge of activated carbon which removes the sediment particles down to a certain size and also free chlorine which is detrimental to the reverse osmosis membrane. Then, in the reverse direction, passes through a...

Dear Helen - Cannot help with the Focus WL450 but we do have the Vertex Reverse Osmosis purification system and yes it was expensive and yes it does remove up to 98% of inorganic ions and virtually All non-ionic particles but I find it EXTREMELY slow and have to make sure I store enough deionised wa...

Dear Rae - A hot 0.1M solution of the tetrasodium salt of ethylenediamine tetra-acetic acid is an excellent solvent for many of the precipitates (except metallic sulphides and ferricyanides), these include barium sulphate, calcium oxalate, calcium phosphate, calcium oxide, lead carbonate, lead iodat...

Thanks for your input Ocker and Tania - think I will have to go with the multimeter idea, replacing the wire does'nt appear to be a simple as I thought and stopping the students from burning out the meters seems to be practically impossible to achieve even with teacher cooperation! Once again - than...

HELP!! How do you good people stop students from blowing the wires in Ammeters/Voltmeters etc. I guess you can have them repaired but where does one go for that? Can it be done by a handy man with the correct wire? Where does one get the correct wire or is it a matter of a Fuse? Would it be cheaper ...

Dear Rae - I used to have one of these deionisers years ago and was able to buy the cartridge from Science Supply Australia phone toll free
1300 857 544 or fax toll free 1300 857 533. Good luck. Judygee
(Regular phone no: 03 9873 2588)

Dear TritonX - Start by getting rid of all unwanted chemicals - you may be able to wash some away, evaporate others, send others off with your regular chemical salvage service. Very important you use the CSIS package (Appendix D) to guide you with the disposals. This package will also be very helpfu...

Dear Di - We have used Robin Parkes from Eyepoint Instruments in the past. He does a very good job however he does charge accordingly!! However if you can get other schools in the area to use his services this may reduce the cost, if it is worth his while to come over the mountain for a number of jo...