I'm going to follow Inoue's protocol for competent E. coli cells. It says that I should incubate it in 250ml SOB medium 18°C-22°C at moderate shaking. Then, I should read the OD600 in the next morning until it reaches 0,55.
How many hours it usually takes for E.coli to grow and reach this OD, under these conditions?
The time needed to reach OD 0.5 depends on several factors
1) Inoculum
2) incubation temperature
3) type of broth used
4) shaking condition (how much rpm)
5) E. coli strain
Normally, I inoculate 1 colony of DH5a into 5ml LBB, shake at 160rpm 37°C, then the next day inoculate the 5ml into 100ml fresh LBB, shake at 160rpm 37°C. Under these conditions, it reached OD(600nm) 0.4 around 3-4 hours. May be you can use this as reference.
Hi there,
It mainly depends on the inoculum (number of viable cells).
you can estimate it if you know the OD600 values of your overnight culture that you use for inoculation. For example the culture has 1,8 at OD600 and you dilute ist 1:100 => 0,018 you can double this value every 20 min (E.coli) until you reach 0,55 to estimate how log you approximately need.
The time needed to reach OD 0.5 depends on several factors
1) Inoculum
2) incubation temperature
3) type of broth used
4) shaking condition (how much rpm)
5) E. coli strain
Normally, I inoculate 1 colony of DH5a into 5ml LBB, shake at 160rpm 37°C, then the next day inoculate the 5ml into 100ml fresh LBB, shake at 160rpm 37°C. Under these conditions, it reached OD(600nm) 0.4 around 3-4 hours. May be you can use this as reference.
I agree with the answers that you have already given. By the description of the procedure you give, you will probably reach that D.O. in 2 or 3 hours. The other thing I would add is that if the strain already has an antibiotic as a selection marker, and you use it, the strain will grow slower than it without the selection marker.
hi, normally we work on fresh bacterial cultures precisely 24h to 36h incubation at 37 ° C, and we adjust the suspension according to the standard mcfarland desired. For example 0.5 McF is 0.08 to 0.1 OD at 600nm .
This process is difficult to predict, so I just check OD 600 every hour or so.
Hi,
It is tough to predict it in real-time experiments. I would suggest you to run a preliminary experiment and calculate the doubling time from it. When you follow the same conditions, your estimated doubling time will help in closely predicting the time required to attain the required growth.
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