Anyone made Phenolphthalein Agar with HCl?

Request or contribute your recipes here. You can also try doing a search, as there are some old recipe posts which have not or cannot be moved over to this forum.
Post Reply
Merilyn1
Posts: 1477
Joined: 12 Mar 2013, 08:10
Job Title: Labbie
School: Wollondilly Anglican College
Suburb: Tahmoor
State/Location: NSW

Anyone made Phenolphthalein Agar with HCl?

Post by Merilyn1 »

The biology teachers want to try the reverse of the normal phenolph agar prac by using agar made with HCl and the students putting NaOH to look at surface area.

Has anyone done it this way? I was just thinking of using the same amount of HCl as I would normally use of NaOH.
User avatar
smiley
Posts: 1398
Joined: 20 Nov 2006, 10:00
State/Location: QLD

Re: Anyone made Phenolphthalein Agar with HCl?

Post by smiley »

Worth a try, but will it set?
Cheers, K 8-)
User avatar
rae
Posts: 1045
Joined: 31 May 2006, 10:00
School: Oxley College
Suburb: Burradoo
State/Location: NSW

Re: Anyone made Phenolphthalein Agar with HCl?

Post by rae »

That was my thought smiley. The HCl may denature the agar and not allow it to set?!
Merilyn1
Posts: 1477
Joined: 12 Mar 2013, 08:10
Job Title: Labbie
School: Wollondilly Anglican College
Suburb: Tahmoor
State/Location: NSW

Re: Anyone made Phenolphthalein Agar with HCl?

Post by Merilyn1 »

Hi All
Jazz helped me out with a recipe. Make up agar, add the phenolphthalein as usual. If it is pink add a few drops of HCl until clear.

I've tried this and it worked fine, even with the addition of a few drops of acid, all has set properly.

Thanks Jazz!
Post Reply