× Didn't find what you were looking for? Ask a question
Top Posters
Since Sunday
7
e
5
e
4
4
d
4
o
3
p
3
t
3
3
m
3
p
3
m
3
New Topic  
micro micro
wrote...
Posts: 170
Rep: 2 0
10 years ago
When determining the incubation period required for a bacteria species/strain to reach a particular growth phase e.g. exponential phase by plotting a growth curve, is there a standard starting OD value? (if one is using turbidity as an indirect method). Most protocols online require an overnight culture and then simply state to add a volume of this culture to another volume of fresh broth; say the exponential phase is determined to be between 3-4 hours, doesn't this indicate that the exponential phase is reached when inoculating an equal volume of broth with bacteria? i.e. if you are inoculating a larger or smaller quantity of broth, I would assume the incubation period required to reach the exponential phase would vary, correct?
Read 2008 times
3 Replies

Related Topics

Replies
wrote...
Staff Member
Educator
10 years ago
HI micro

I totally missed your thread. What did you end up discovering here.

Sorry about that.
Mastering in Nutritional Biology
Tralalalala Slight Smile
micro Author
wrote...
10 years ago
Nothing so far Face with Stuck-out Tongue
wrote...
10 years ago
If there is nothing in the literature about the replication time for the bacteria, here is what I would do.

First inoculate a flask from a colony and let it grow overnight.  The next day you will have a flask that is in lag phase.  Next I would dilute the starter culture to a range of concentrations.  For instance, start 4.95mL of media, then add 50uL of the o/n culture,  4.9mL media and 100uL of the on/ culture.  I would do a series of 50uL, 100uL, 250uL, 500uL, and 1mL of the o/n culture to enough media to equal 5mL.  Then check each dilution by spec periodically to see the growth and write them down.  One of those will assure you get a low enough starting concentration to see the growth curve without having to spend extra time in lab cause you diluted to too low of an initial starting concentration.

Hope this helps!
New Topic      
Explore
Post your homework questions and get free online help from our incredible volunteers
  943 People Browsing
Related Images
  
 640
  
 66
  
 722
Your Opinion
Who's your favorite biologist?
Votes: 587

Previous poll results: What's your favorite math subject?