TSS

Uses

TSS buffer is used to make chemically competent cells.

Preparation

To make 50 mL:

• 5g PEG 8000
• 1.5 mL 1M MgCl₂ (or 0.30g MgCl₂*6H₂0)
• 2.5 mL DMSO
• Add LB to 50 mL

Filter sterilize (0.22 μm filter)

Notes

• Note 1: pH from original Chung CT paper calls for pH to be acidic (pH=6.5)... be sure to pH solution before sterilization
• Note 2: If using non-chemically resistant filters (e.g., cellulose nitrate), add DMSO after sterilization. DMSO should be sterile in and of itself, so it may be prudent it add it afterwards if you are unsure about the compatibility of your filters.

Storage

Store at 4˚C or -20˚C.