Check for insolubility – this is important because uncontrolled T7 expression often leads to very high production of protein that can result in the target protein becoming insoluble. Solutions around this are:

• Induce at a lower temperature (20 to 30°C)
• Induce earlier in growth phase (OD₆₀₀ = 0.3 or 0.4)
• Test expression using a full range of L-rhamnose concentrations: 0 to 2,000 µM (see figure on the main product page).