Also worked in lab diagnostics for quite a while. You're correct about the process. I'd add that the only particularly expensive piece of hardware along the chain is the light detection at the end. Sure, you need high precision pumps to dispense reagents & sample accurately, but if you're not running at industrial scale, those aren't that hard to DIY. And, of course, some reagents will be expensive as you said.
On the machines we built, the reaction products bound to a light-emitting material and we used photomultiplier tubes to measure the light output at the end. I believe this is more sensitive than the occlusion/scattering methods in the article. The problem is that PMTs are pretty expensive to buy new and their calibration needs to be checked periodically.
I have wondered if it would be possible to make a cheaper version using large-area PIN diodes, or with lenses to collect as much light as possible. Never saw any research being done in this area though.
Comments
Also worked in lab diagnostics for quite a while. You're correct about the process. I'd add that the only particularly expensive piece of hardware along the chain is the light detection at the end. Sure, you need high precision pumps to dispense reagents & sample accurately, but if you're not running at industrial scale, those aren't that hard to DIY. And, of course, some reagents will be expensive as you said.
On the machines we built, the reaction products bound to a light-emitting material and we used photomultiplier tubes to measure the light output at the end. I believe this is more sensitive than the occlusion/scattering methods in the article. The problem is that PMTs are pretty expensive to buy new and their calibration needs to be checked periodically.
I have wondered if it would be possible to make a cheaper version using large-area PIN diodes, or with lenses to collect as much light as possible. Never saw any research being done in this area though.