Calculations help

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RAZriz
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Calculations help

Post by RAZriz » Wed Aug 24, 2011 3:10 pm

Hi i was wondering if you can help me i have a total volume of 400ul. I have a reagent that is 100ng/ml in 20ug/ml stock. I was wondering what is the volume of the reagent i need to add to the 400ul. Can you also show me the calculations

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JackBean
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Post by JackBean » Wed Aug 24, 2011 6:46 pm

use the simplest formula ever c1V1 = c2V2
the stock is 20 ug/ml and final conc. should be 100 ng/ml, right? So, c1 = 100 ng/ml; V1 = 400 ul; c2 = 20 ug/ml and V2 you calculate ;)
Otherwise you can think, that you need to dilute it 20 000/100 = 200-times, so the volume must be 200-times smaller i.e. 400/200 = 2 ul :)
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Post by RAZriz » Thu Aug 25, 2011 8:35 am

Thanks for your help. I also need help with this: The reagent is 1mg/ml in PBS that is 500x there is a aliquot of 5x0.1ul. I was wondering how much would i need to add to a 50ml solution. I would be grateful if you can show me the calculations aswell thank you

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Post by RAZriz » Thu Aug 25, 2011 8:56 am

Sorry I need to add 2ug/ml to the 50ml solution

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JackBean
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Post by JackBean » Thu Aug 25, 2011 9:47 am

I'm sorry, I didn't get that
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Post by RAZriz » Thu Aug 25, 2011 10:07 am

I have a reagent that is in PBS at 500x (1mg/ul) I need to know how much i need to add to a 50ml solution so the concentration would be 2ug/ml

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canalon
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Re:

Post by canalon » Thu Aug 25, 2011 2:24 pm

RAZriz wrote:I have a reagent that is in PBS at 500x (1mg/ul) I need to know how much i need to add to a 50ml solution so the concentration would be 2ug/ml

50/500= ? That is what 500x mean, divide your final volume by the concentration factor (here 500) and you know how much to use.
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