CODEX® Multiplexed Imaging | Tissue Sectioning

Gather reagents:

Gently place coverslips at the bottom of a 500-mL glass beaker and swirl to spread the coverslips out. Add approximately 20mL poly-L-lysine solution to the beaker, ensuring coverslips are fully submerged. Rotate the beaker at a 45° angle for 0h 1m 0s to mix.

Cover beaker with parafilm and incubate for minimum of 12h 0m 0s at Room temperature. Coverslips can sit in the poly-L-lysine solution for up to one week.

Slowly pipet off the poly-L-lysine solution and dispose.

Fill the beaker containing the coverslips to half volume with Milli-Q® water. Swirl gently, let sit for 0h 0m 30s, and then slowly pour off water into the sink.

and repeat for a total of 5-7 washes.

Spread WypAll® towels on the benchtop. In small batches, remove coverslips from the beaker, separate from one another, and place individual coverslips side by side on towels. Layer another towel on top and gently dab to remove excess liquid. Leave on benchtop until completely dry.

ⓘ Coated coverslips can be stored in a petri dish for up to 2 months.

Set the cryostat temperature to -20°C. Remove a fresh blade, clean with ethanol and a lint free wipe as needed, and insert blade.

Using OCT or CMC, mount sample onto the cryostat chuck in the desired orientation. Trim CMC using larger section increments of 30-50 μm until the tissue becomes visible ( Figure 1a ).

Obtain 6 µm to 10 µm sections, using a fine-tipped paintbrush to guide the section onto base and place coverslip onto section ( Figure 1b-1d ).

Using forceps, slot coverslips with mounted tissue into a plastic coverslip holder under the appropriate donor/block ID label(s).

As necessary, mount adjacent sections onto Gold Plus slides (for traditional immunohistochemistry) and/or ITO slides (for mass spectrometry). Record all sections cut, the thickness, and any additional block shaved off in the process.

3D printed coverslip holders: Codex Rack MkIII-Body.stl

We use these with the following:

Store coverslips at -80°C for up to 6 months.