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TLS Online TPP Program

#Question id: 13057

Precision will be reduced, but yield will be increased
Optimisation of a PCR reaction is often a compromise between the competing demands for precision, efficiency and yield. Although the specific effects may vary, generally, increasing the annealing temperature will increase non-specific primer binding and reduce precision. Increasing the length of the elongation phase will reduce the proportion of incomplete newly-synthesised strands and therefore increase yield. In this case, the potential effect on efficiency is unclear. Increasing the elongation phase would increase the reaction time, but the time taken to ramp down to a lower annealing temperature would be reduced.
How primer concentration leads to decrease in PCR efficiency?

#Part-A Aptitude & General Biotechnology
  1. Primer concentration decreases with time
  2. Binding specificity of the primer reduces over cycles
  3. Base pairing between the primers reduces their availability
  4. Excess template leads to competition for primer
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TLS Online TPP Program

#Question id: 14217

#Part-B Specialized Branches in Biotechnology

In a microbial system how true yields are related to apparent growth yield? 
TLS Online TPP Program

#Question id: 14218

#Part-B Specialized Branches in Biotechnology

In CSTR system at steady rate  
TLS Online TPP Program

#Question id: 14218

#Part-A Aptitude & General Biotechnology

In CSTR system at steady rate  
TLS Online TPP Program

#Question id: 14221

#Part-B Specialized Branches in Biotechnology

E. coli have a maximum respiration rate, qO2max, of about 240-mg O2/g-dry wt-h. It is desired to achieve a cell mass of 20 g dry wt/l. The kLa is 120 h-1 in a 1000-l reactor (800 l working volume). A gas stream enriched in oxygen is used (i.e., 80% O2) which gives a value of C* = 28 mg/L. If oxygen becomes limiting, growth and respiration slow; for example,

                                     
   where CL is the dissolved oxygen concentration in the fermenter. What is CL when the cell mass is  at 20 g/l?
TLS Online TPP Program

#Question id: 14237

#Part-B Specialized Branches in Biotechnology

A genetically-engineered strain of yeast is cultured in a bioreactor at 30⁰C for production of heterologous protein. The oxygen requirement is 80 mmol 1-1 h-I; the critical oxygen concentration is 0.004 mM. The solubility of oxygen in the fermentation broth is estimated to be 10% lower than in water due to solute effects. What is the minimum mass-transfer coefficient necessary to sustain this culture if the reactor is sparged with air at approximately 1 atm pressure ?         
TLS Online TPP Program

#Question id: 14238

#Part-B Specialized Branches in Biotechnology

A genetically-engineered strain of yeast is cultured in a bioreactor at 30⁰C for production of heterologous protein. The oxygen requirement is 80 mmol 1-1 h-I; the critical oxygen concentration is 0.004 mM. The solubility of oxygen in the fermentation broth is estimated to be 10% lower than in water due to solute effects. What mass-transfer coefficient is required if pure oxygen is used instead of air?