Australia's Science Forum

Hi all,
Here is another one for you experienced Labbies. My Bio teacher wants some PHLOROGLUCINOL stain made up (for staining Lignin). I have the powder, but have no idea of how to make it up into a useable stain. It does not seem to be in my list of stains. Any ideas?
Regards
Ian

Hi Ian,

Certainly an easy one - Dissolve 1 g Phloroglucin in 100 mL of 50% Ethanol and 50% Water

Add the Ethanol first then dilute to 100mL with water.

This will certainly get the ball rolling for you.

Robb....

Dear Ian, I see Robb has given you a recipe for this stain, mine is a little different: 0.1g of Phloroglucinol to 70% ethanol solution. Just a little tip that caught me out a few years ago - Prepare the solution several weeks before being used and then mix with Conc. HCl Mix 100ml Phloroglucinol solution with 20ml Conc. Hydrochloric acid. Put into small dropper bottles and label well. We usually use a very small amount of sawdust from the TAS dept (or shredded paddlepop sticks) in large test tubes, with excellent results. Cheers Judy.

Hi Ian,

There is also a recipe for phloroglucinol given in the CSIS Manual, Appendix D page 253 (listed under 1,3,5-trihydroxy-benzene). This recipe is similar to Judy's recipe, i.e. it is dissolved in ethanol and then combined with conc HCl. We have found this works well.

Robbie