Push–pull perfusion
Push–pull perfusion is an in vivo sampling method most commonly used for measuring neurotransmitters in the brain. Developed by J.H. Gaddum in 1960,[1] this technique replaced the cortical cup technique for observing neurotransmitters. The advent of concentric microdialysis probes in the 1980s resulted in push-pull sampling falling out of favor, as such probes require less monitoring, and are less invasive than the higher flow rate push-pull probes (>10 microliter/min), which could result in lesions if flow is unbalanced.[2]
With the advent of microfluidics and miniaturized probes, low-flow push–pull sampling was developed in 2002.[3] By using flow rates of ~50 nL/min, this technique minimizes tissue damage while providing finer spatial resolution than microdialysis sampling.
