READOUTS

How do you know it worked?

A clear chip lets you image cells with a microscope. Dyes show leaks, stains show proteins, and the fluid leaving the chip can be collected and analysed.

An organ chip is only as useful as what you can measure from it.

TEER

Measuring barrier tightness

Transepithelial or transendothelial electrical resistance (TEER) passes a tiny current across the cell layer. Tight barriers resist current more. It is quick, label-free and can be repeated every day.

TEER is a non-destructive health check for barrier tissues.

PERMEABILITY

How much gets across?

🧪

Add a tracer Put a fluorescent molecule in one channel

Collect Sample the other channel over time

Calculate The apparent permeability, P_app, from how fast it crosses

Compare Small vs. large tracers show how tight the barrier is

Permeability tells you how much of a drug could actually get through.

BUILT-IN SENSORS

Watching in real time

🫧

Oxygen

Optical spots or electrodes track how much oxygen cells use

🧪

pH and glucose

Show how hard the cells are working

⚡

Electrodes

Record TEER or heart and nerve cell activity continuously

Built-in sensors turn a snapshot into a movie.

WHAT COMES OUT

Reading the effluent

🧴

🫘

Albumin and urea

Show that liver cells are doing their job

💥

LDH

An enzyme released when cells are damaged

🔥

Cytokines

Signals of inflammation

The fluid leaving a chip carries a record of what the tissue did.

UNIT 18 STUDY COMPLETE

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Ready for the Fab Challenge?

You've seen how organ chips are measured: imaging, TEER, permeability, built-in sensors and analysis of the fluid coming out.