why we should use only 0.45 micron filter in sterility test, 0.1 micron size bacteria also present
Because Sterility test is a recovery test as during manufacturing there is a filtration process which uses 0.2 micron filter and moreover many microorganisms get killed during autoclaving process.
Sorry i am not understand what u say,
Please clarify in detail
During mfg process there is a step known as filtration in which 0.2 micron filters are used which is known as retention step. In sterility we have to find out the microorganisms not to remove them. This is known as recovery test.
As Vivek mentioned above it is a recovery test where 0.4 micron can retain the microbes whreas 0.2 micron can not retain microbs in the pores.
Can any one explain in detail for @mahesh27042 question…
we use 0.45 micron filter then microorganisms could be easily retained on the filter paper and the applied vacuum will not have impact on the viability of the microorganism involved in the test but if we use 0.22 micron filter paper stringent pore size and applied vacuum leads to damage of microbial cell which will not further recover during the incubation time. That’s why we use 0.45 micron pore size filter for sterility testing.
But during filtration of disinfectants or any liquid batch we use 0.22 micron pore size filter because in that our main purpose is to get sterile solution by removing the contamination from the solution whether live or dead it doesn’t matter but the thing matters is that the solution must be sterile. Filtration is one of the method of sterilization. So, by filtering through 0.22 micron filter all form of contamination could be removed. That’s why we use 0.22 micron pore size filter for filtration.