Vishnu Kanth

14 Questions 15 Answers 0 Followers

Questions related from Vishnu Kanth

Why is DO dropping to zero after three hours of inoculation?

We do G-CSF fermentation using recombinant E.coli cells. After inoculating into the fermenter following a successful media hold, Dissolved oxygen % is dropping to zero within three hours. Oxygen...

12 November 2017 3,691 11 View

What happens during continuous usage of spectrophotometer?

If a spectrophotometer is used continuously for three days without turning the lamps off in between, how could it affect the readings?

28 June 2017 739 3 View

What are the chances of impurities at the end stage chromatography?

What are the chances of impurities at the end stage chromatography? What all can lead to this? How to rectify?

18 March 2017 9,011 3 View

How to calculate lysis efficiency during microbial cell lysis?

How to calculate lysis efficiency during microbial cell lysis by high pressure homogenizer?

18 March 2017 5,612 0 View

Can someone explain Measurement, Offset and Slope of a pH meter?

Can someone please explain Measurement, input, offset and slope of a pH transmitter. My transmitter gives slope in the range of 12-25% mA. What does that mean? How do I compare it with 92-102%...

08 July 2016 4,912 4 View

Why do inline and offline pH probes show different values?

Inline pH probe and offline desktop pH probe, calibrated with same buffers show different pH of a solution at the same time. What can be the reason?

24 June 2016 3,174 4 View

Which bacteria look similar to E coli under 100X microscope?

Which bacteria look similar to E coli under 100X optical microscope? In a E coli fermentation culture, which contaminants look like E coli? How can we distinguish them?

18 February 2016 4,538 4 View

Does a new pH probe need polarization before use?

Does a new pH probe need polarization before use? We need to polarize a DO probe before use. What steps are to be followed to use a new pH probe?

24 October 2015 4,334 2 View

Can anyone please explain what exactly is the integral of viable cell concentration and explain how it is calculated?

Details of IVCC needed

20 July 2014 9,282 4 View

How much is the effect of Antifoam on the growth of E.coli during fermentation?

Antifoam concentration and it´s effects on growth of E.coli.

06 April 2013 636 3 View

When exactly should the 100% calibration of a DO probe be done during fermentation? When the media is saturated in normal conditions or at the highest condition?

During cascading events of a fermentation, agitation and aeration are at a max. Thus the saturation of air with those conditions give a higher DO value compared to the saturation using basic...

28 February 2013 2,387 10 View

How exactly does a water intrusion test work using hydrophobic filters?

Water and vapor inter conversion inside the filter in between the membranes is unclear to me. Can anybody help me out?

28 February 2013 7,013 2 View

What would be the main differences between a culture grown in ready made chemical media and a media made of individual raw materials?

Which factor would play the major role if culture of E.coli is grown in ready made media (LB) and media made of raw materials (yeast extract and dextrose)?

27 February 2013 4,772 0 View

During E.coli fermentation, DO rises and falls for a short time after two hours of incubation (every time). Can anyone tell me why?

Fed Batch fermentation and 10L working volume.

25 February 2013 7,313 10 View