Question

Heat shock method uses ___________

(a) Calcium rich environment

(b) Magnesium rich environment

(c) Potassium rich environment

(d) Sodium rich environment

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This is a very interesting question from Guidelines for Choosing Host-Vector Systems topic in section Utilizing Genetically Engineered Organisms & Medical Applications of Bioprocess Engineering of Bioprocess Engineering

Answer 1

Right answer is (a) Calcium rich environment

To explain: In the laboratory, bacterial cells can be made competent and DNA subsequently introduced by a procedure called the heat shock method. Heat shock transformation uses a calcium rich environment provided by calcium chloride to counteract the electrostatic repulsion between the plasmid DNA and bacterial cellular membrane.