Question about bacteria sensor

[Ram Kumar Koppu]

Hi,

Yesterday's meetup was nice.

I was watching video recording of previous event Biomaker Meetup: Build a bacteria sensor by Adrian Filip (https://youtu.be/AKT3btoIab8), As per google search, The smallest bacteria are about 0.4 micron (400nm), I was wondering how will these light particles (he was using 600nm LED light) detects smaller bacteria? 

I am from Embedded Software (Electronics & Software, ML) so, no means expert in Biology to do further research on this. I thought someone in the group knows the answer. 

Regards,

Ram

[Tony Naggs]

Hey Ram

There is a Makespace Biology Club (https://biology-club.makespace.org/) with its own google group, which is probably a better place to ask biology questions.

I'm also a hw/sw engineer, but as I understand it the light sensor is measuring the opacity of the sample. So for example a bacteria sample is added to nutrients and warmed to its preferred temperature (eg 36 degrees C), and the opacity could be measured every few hours (growth will slow when nutrients become scarce). Or two cultures could be cultivated, maybe one is genetically modified or has an proposed antibiotic added, after say 24 hours the cultures would be compared.

Cheers,

Tony