Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta
    • Thread Starter
    Offline

    9
    ReputationRep:
    You have reached the maximum response for the drug you are testing but when you plot the data you realise you need a response value for -7.5 on your log [Drug(M)] scale.You have a stock solution of 1µM and the organ bath is 10 ml, what volume (in µl) of this stock will you need to add?


    (Give your answer in microlitres to 3 significant figures. Do NOT include units when you type in your answer).

    ** BTW I DON'T JUST WANT AN ANSWER I NEED TO KNOW HOW TO TACKLE THESE KINDS OF PROBLEMS, SO A STEP BY STEP KIND OF THING WOULD BE GREAT**
    many many thanks !
    Offline

    3
    ReputationRep:
    -Determine the concentration that gives a response rate of -7.5 from graph
    -Use the equation C1V1=C2V2 to determine the volume of stock solution required to prepare a 10mL solution of the concentration determined using graph.

    That's the best I can do with the amount of info you've provided. Hope this helps
    Offline

    5
    ReputationRep:
    First, unlog the log[drug] value (mostly likely a log10). This gives you the concentration you're looking for in the organ bath, in this case 10^(-7.5)M.
    Then, work out how much 1uM solution you need to add to 10ml water to make this concentration.
    So (10^(-7.5))/(10^(-6)) = 0.0316..., this is how much you need to dilute the stock to get a concentration of 10^(-7.5)M.
    Then, you want to make up this concentration in 10ml water, so times by 10 for an answer of 0.316ml or 316ul.

    Is that right?


    Posted from TSR Mobile
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: October 27, 2015
Poll
Are you going to a festival?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.