1. Transformation
2. Plasmid isolation
3. PCR
4. DNA purification
5. Restriction digestion
6. Ligation
7. SEM assay
8. DLS assay
9. Spectrophotometry assay
10. Reagents

Transformation

Preparation of competent cells - TSS method

Day 1

Step	Description	Rationale
1	Prepare a primary inoculum of E. coli in 5 mL LB in a test tube.	-
2	Incubate overnight at 37°C, 170 rpm.	-

Day 2

Step	Description	Comments
1	Inoculate 1 mL overnight culture in 100 mL LB medium (1% inoculum)	Depending on how many aliquots of competent cells you wish to make, you can vary the volume of LB medium used. This protocol yields 1 aliquot per mL of LB medium.
2	Incubate at 37°C, 170 rpm until the OD reaches 0.4 (~1 h 45 min for E. coli DH5α cells)	This is the early exponential phase; cells are physiologically ideal for the preparation of competent cells.
3	Place the culture at 4°C for 45 min	-
4	Spin down the culture at 10000 rpm, 10 min, 4°C	-
5	Resuspend the cell pellet in 1 mL ice-cold TSS buffer	-
6	Spin down the culture at 10000 rpm, 10 min, 4°C	-
7	Make 50-100 uL aliquots in chilled microfuge tubes, snap-freeze in liquid nitrogen and store at -80°C for long-term storage	-

Heat-shock transformation

Plasmid isolation

Miniprep

Midiprep

PCR

Simple PCR

Overhang PCR

Colony PCR

DNA purification

Chloroform extraction

Gel purification

Restriction digestion

Single digestion

Double digestion

Overnight digestion

Ligation

Simple ligation

Sequential ligation

Multi-ligation

Scanning Electron Microscopy (SEM) assay

Dynamic Light Scattering (DLS) assay

Spectrophotometry assay

Stocks

LB medium

TSS buffer

Chloramphenicol stock solution