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Hi,

 

Can someone please tell me if I am doing the right calculation here.

 

So, the question is if had to make 50ml of a 2.0 % agarose gel, how much agarose would I need to weigh out?

 

 

So I find 2% of 50ml:-

 

2.0x50ml = 100 g of agarose ? is this correct ?

 

 

And I need to calculate how much of a 6 X loading buffer I need to add to my PCR sample, but I am not sure how to do that. Can someone please help? Many thanks

For a 2% gel you need to know the weight of 50 ml water and take 2% of that weight in agarose. There are different types of loading buffers (though with overall similar to same composition). As a rule of thumb X-buffers are used in 1x final concentration (though in cases of some universal buffers, they are not).

When making gels, I assume 1ml of water = 1g. So your answer would be correct.

Hang on, I thought the % method referred to weight per volume, e.g. 5% of agarose would represent 5 g dissolved in, and made up to 100 ml. I don't think I need to say more because this is homework help.

Yes, Jimmy is right.