Imagine an air (aerosolic) sample taken from a chicken house facility using a filter device. The aim is to collect (pathogenic) bacteria, supend them in an aqueous based solvent and use them for a MALDI-TOF measurement. In principal, the sample arrives in a given volume and form (since we are working with the german industry norm, DIN), which means the suspension contains all kinds of plant fibres and bacteria in the range of 10^6 per mL. Usually, centrifugation is used as the pre-prep method to concentrate the bacteria. The measurements performed until now where good in cases where the samples contained little to no plant material. However, if the latter is present, there is massive interference. We couldn't separate the very small fibres via filter devices, since they clog every membrane. Standard centrifugation is not an option, since the very small fibres and bacterial cells have very similar densities. Without using intricate technical equipment, is there any simple way we are overlooking at the moment to isolate the pure bacterial cell fraction from the fibres?
Hi Johannes,
You present an interesting question for achieving gross bacterial separation from grossly contaminated aerosol for measurement with a state of the art method. I would not give up quite yet on differential filtration whereas multiple filter porosities (pre filters) can be employed and I would start with 50 micron and work my down from there.
Hi Johannes,
You could try passing the liquid through a sterile cotton containing syringe. I have tried it and worked. It keeps the debris and let the bacteria pass. Then centrifuge the liquid and you have only the bacteria.
Regards
- Badges
- Science topic
- Similar topics
- Biological Science
- Microbiology