SultanOE
Badges: 12
Rep:
?
#1
Report Thread starter 1 year ago
#1
I have been provided with a sample containing 20ug/ul of DNA. The values for Tube 1 have been provided: CONC. OF DNA = 20ug/ul, VOL. OF WATER ADDED = 0ul, FINAL VOLUME OF DNA = 100ul, FINAL VOLUME IN TUBE = 100ul. Tube 2 is a dilution of Tube 1. The values for Tube 2 that have been given are: CONC. OF DNA = 2ug/ul, FINAL VOLUME IN TUBE = 100ul. I need to find the volume of water added and the final volume of DNA but I don't know how. Can anyone help?
0
reply
BobbJo
Badges: 12
Rep:
?
#2
Report 1 year ago
#2
10 microlitres of DNA and 90 microlitres of water
0
reply
SultanOE
Badges: 12
Rep:
?
#3
Report Thread starter 1 year ago
#3
(Original post by BobbJo)
10 microlitres of DNA and 90 microlitres of water
How did you work this out?
0
reply
BobbJo
Badges: 12
Rep:
?
#4
Report 1 year ago
#4
(Original post by SultanOE)
How did you work this out?
For 20 ug/ul -> 2 ug/ul, the concentration goes down by 1/10. Hence you need 1/10 as much DNA

so only 10 uL of DNA is needed. you add 90 uL on water to make volume to 100 uL. this 100uL contains only 1/10 the DNA in the original tube. so the concentration is 1/10 the original which is 2 ug/ul which is exactly what we want
0
reply
SultanOE
Badges: 12
Rep:
?
#5
Report Thread starter 1 year ago
#5
(Original post by BobbJo)
For 20 ug/ul -> 2 ug/ul, the concentration goes down by 1/10. Hence you need 1/10 as much DNA

so only 10 uL of DNA is needed. you add 90 uL on water to make volume to 100 uL. this 100uL contains only 1/10 the DNA in the original tube. so the concentration is 1/10 the original which is 2 ug/ul which is exactly what we want
and what if for tube 3, the DNA conc is 1ug/ul?
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

University open days

  • University of Hertfordshire
    All Subjects Undergraduate
    Sat, 22 Feb '20
  • Ravensbourne University London
    Undergraduate Open Day Undergraduate
    Sat, 22 Feb '20
  • Sheffield Hallam University
    Get into Teaching in South Yorkshire Undergraduate
    Wed, 26 Feb '20

People at uni: do initiations (like heavy drinking) put you off joining sports societies?

Yes (317)
65.77%
No (165)
34.23%

Watched Threads

View All
Latest
My Feed