June 04, 2020, 11:38:33 AM
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### Topic: Conc. of bio solns  (Read 4546 times)

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#### socomplicated

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##### Conc. of bio solns
« on: September 02, 2004, 05:48:18 PM »
here is a part of the protocol we did:

a)spin down the chloroplast solution and decant the supernatant. add 4ml water to the pellet.

b) add 10ul proteinase K ( concentration= 20mg/ml) to get a final concentration of 50ug/ml.

-> how do they get 10ul? which formula do they use? i don't think that they use the dilution formula (C1 XV1= C2 X V2) since we don't know the total volume of the solution. it can't be 4ml, because when we add proteinase K the volume of the solution will increase.

c) then add slowly 0.25ml 10% or 0.125ml 20% SDS to get a final concentration of 0.5% SDS.

-> again, how do they come to 0.25ml 10% or 0.125ml 20% SDS to get a final concentration of 0.5% SDS?

i am very stucked, please *delete me*
« Last Edit: September 05, 2004, 11:16:24 PM by hmx9123 »

#### Mitch

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##### Re:how come, how come???!!!
« Reply #1 on: September 02, 2004, 07:11:25 PM »
c.) When it says % SDS it most likely means volume/volume. For the 10% case add 0.025ml SDS and 0.135ml water. Or scale it up accordingly.
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#### savoy7

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##### Re:Conc. of bio solns
« Reply #2 on: February 03, 2005, 03:02:58 AM »
SDS can be purchased as a solid - if it is - usually % is grams/ml
so grams of sds/ml total solution