c*****t 发帖数: 1879 | 1 Perfectly normal.
The bacterial was not in growth phase. It could be caused by
1. high cell density. O.D. can mislead you sometimes because
that can vary for different strains. But don't people
usually use OD 600 (598) to check cell density?
2. the cells were in cold for a period of time.
3. lack of oxygen. | R*s 发帖数: 2041 | 2 1. never heard of measuring bacterial at OD546 and calculating as u
said below. We only do it at OD600.
2. What temperature you grow the cells? Hope it is 37, not 30.
BL21(DE3)Plyss does grow relatively slower than other E.Coli strains.
However, it is not as slow as yours.
3. In fact, 12 hours for your transformed culture to reach OD 0.8 is not
terribly slow. It usually take us 6-9 hours to do so.
4. Last suggestion, make sure your Amp and Chl concentration is correct.
Even if they are correct, |
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