No expression in E. coli fed-batch culture on M9 media, but good expression on M9 in erlene-meyer flask?

we get excellent expression on LB and M9 in flask, but no expression in the fed-batch cultures in bioreactor. we have an E. coli bl21(DE3) transformed with pet-24a

08 September 2017 6,248 6 View

Does ompA peripelasmic secretion signal cleave specifically and completely from the N-terminal of recombinant proteins expressed in E. coli?

We're expressing recombinant hGH in E. coli using the ompA peripelasmic secretion signal for soluble expression. From our SDS-PAGE and SE-HPLC results we really doubt if the ompA signal peptide is...

07 August 2017 8,561 2 View

Physics: Why do we describe light by referring to its wavelength, but microwaves and radar pulses by referring to their frequency?

In physics, the description of the properties of light generally refers to its wavelength (nm), while in the range of microwaves and radio waves we refer to the frequency of a signal (e.g. kHz or...

03 March 2021 1,682 3 View

Does any one know how i can prepare liver tissue with transmission electron microscope with good fixation?

i have problem in preparation of liver tissue with bad cell organelles and how i can adjust osmolarity

03 March 2021 8,890 1 View

Is there any effect of different colours of light (white, red, yellow, blue etc.) on the rate of photosynthesis? If yes, why?

Light is inevitable for the process of photosynthesis reaction. Naturally sunlight plays the vital role for this process. Light may be of different colours like white, red, yellow, blue etc....

02 March 2021 7,890 2 View

Can someone suggest a way to prepare slides to observe under confocal microscope for observing fluorescent tagged proteins??

I am growing the cells on coverslips and transfecting the fluorescent tagged protein directly on them. Then i want to observe these cells under confocal microscope. Currently i am just using...

01 March 2021 6,142 3 View

In an eye with Tyndall, does each dot correspond to an individual cell?

When you observe the presence of Tyndall in an inflamed eye: Does each of the small floating dots correspond to an individual cell or to an aggregate of cells? Does a conventional slit lamp have...

27 February 2021 6,326 2 View

How can I obtain time series data by country on night-time light (brightness) ?

Hi everyone, Please, how can I obtain time series data by country on night-time light (brightness) ? I've tried, but so far all I can find are maps. I am looking for numerical data, especially in...

24 February 2021 8,625 4 View

What are difference between laser diodes, simple light emitting diodes and power light emitting diodes when operated in the visible spectrum ?

I want to illuminate a scene (small space) using LED to capture photographs or videos of some tiny objects inside the space. But am not sure if I should use a Laser LED, or simple LED or power...

22 February 2021 4,240 4 View

How to interpret this FTIR spectrum of pyrolyzed hydrochar?

20 February 2021 2,840 3 View

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The regenerated cellulose film was prepared by zinc chloride/H2O system. The zinc chloride had been washed away in the regeneration process, and the wet film which was not dried had uniform...

18 February 2021 9,538 1 View

How do I plot Pressure against crank angle degree in Fluent?

18 February 2021 8,390 3 View