Detection of Enteric Bacteria in Raw Food Samples from Vietnam ...

2.2.4. Methods of DNA analysis ................................................................................. 72
2.2.4.1. Agarose gel electrophoresis ...................................................................... 72
2.2.4.2. DNA extraction ........................................................................................ 72
2.2.4.3. Polymerase Chain Reaction ...................................................................... 73
2.2.4.3.1. Design of primers .................................................................................. 73
2.2.4.3.2. General PCR procedure. ........................................................................ 73
2.2.4.3.3. General Expand PCR procedure. ........................................................... 74
2.2.4.4. Purification of DNA from agarose gel electrophoresis and PCR products75
2.2.4.5. DNA sequencing ...................................................................................... 75
2.2.4.6. DNA sequence analysis ............................................................................ 75
2.2.4.7. Restriction enzyme digestions .................................................................. 76
2.2.4.8. Transformation of DNA ........................................................................... 76
2.2.4.8.1. Preparation of competent cells .............................................................. 76
2.2.4.8.2. Electroporation of competent cells ........................................................ 76
2.2.4.9. Southern blotting ...................................................................................... 77
2.2.5. Tissue culture techniques .................................................................................. 78
2.2.5.1. Tissue culture cell line .............................................................................. 78
2.2.5.2. Maintenance and storage of tissue culture cell line .................................. 78
2.2.5.2.1. Storage of stock cultures- banking down and reconstitution ................. 78
2.2.5.2.2. Tissue culture growth conditions ........................................................... 79
2.2.5.3. Invasion assay ........................................................................................... 79
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