PAG 1.2 Blood smear - Buffered water?

Hello! I'm preparing the PAG 1.2 using horse blood and it says I need buffered water and gives a recipe to make it. Does anyone know if this is the same as the buffer solutions we buy in? I have a range of pH's so assumed a pH 7 would work. It would be great if i didn't have to make up buffered water as we don't have the chemicals it mentions.

Thank you!
 

CovTech

Lvl 37 Alchemist
COMMITTEE
That's probably to put the blood in a pH range so that it won't degrade as quickly using only chemicals which don't denature the blood itself

I would be hesitant guessing if a standard pH7 would do that without researching what the pH should be from the PAG and what the chemicals used in your bought in buffer are as there are so so sooo many variants on "pH 7 buffer" composition

Best bet if you're really stuck might be to try a small amount of the blood and trial the prac using that but if it doesn't work you're stuffed and will have a ruined blood sample to boot as if I remember doing this years ago correctly it has to be as fresh as possible so won't keep while you order the correct buffer ingredients
 
should be fine with pH 7, blood is around pH 7.2 but does depend on the pH of the stain you intend to use if any. Like CovTech say have a play using a small amount to see haw it reacts, stains and preserves
 
The phosphate buffer recipe on CLEAPPS uses sodium dihydrogen phosphate and disodium hydrogen phosphate, but does say potassium salts could be used. This seems similar to the buffered water recipe suggested for PAG1.2, so if you have a phosphate buffer you may be ok.
 
The phosphate buffer recipe on CLEAPPS uses sodium dihydrogen phosphate and disodium hydrogen phosphate, but does say potassium salts could be used. This seems similar to the buffered water recipe suggested for PAG1.2, so if you have a phosphate buffer you may be ok.
If my calculations are correct (dubious having been on holiday for 2 weeks) the buffered water recipe seems to work out to the equivalent concentrations for the pH7 phosphate buffer recipe.
 
Hello! I'm preparing the PAG 1.2 using horse blood and it says I need buffered water and gives a recipe to make it. Does anyone know if this is the same as the buffer solutions we buy in? I have a range of pH's so assumed a pH 7 would work. It would be great if i didn't have to make up buffered water as we don't have the chemicals it mentions.

Thank you!
only done osmosis with blood, they can burst, is there anything else in it?
 

Peter Sigsworth

COMMITTEE
Hello! I'm preparing the PAG 1.2 using horse blood and it says I need buffered water and gives a recipe to make it. Does anyone know if this is the same as the buffer solutions we buy in? I have a range of pH's so assumed a pH 7 would work. It would be great if i didn't have to make up buffered water as we don't have the chemicals it mentions.

Thank you!
I take it this is AQA? PAG 1.2 is meaningless to those who don't do AQA - please use the prefix to specicy the board, edit your first thread accordingly, thanks
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The phosphate buffer recipe on CLEAPPS uses sodium dihydrogen phosphate and disodium hydrogen phosphate, but does say potassium salts could be used. This seems similar to the buffered water recipe suggested for PAG1.2, so if you have a phosphate buffer you may be ok.
We do OCR and as LyndaR says, you can use the potassium salts to make your buffer if you don't have the sodium ones. That's what we do, and it's absolutely fine.
Also, we don't order in horse blood - the students use their own, which is much cheaper, always fresh, AND they get the "wow" factor that these cells they're looking at were whizzing round their bodies just minutes previously! So long as your school isn't under a local ban, they are allowed to do this - CLEAPSS have a helpful document entitled "studying blood" which is worth a look.
It's one of my favourite pracs :)
 
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