Millipore Filter
Definition and meaning of Millipore Filter in chemistry.
A Millipore filter is a microporous membrane filter with pore sizes typically ranging from 0.025 to 10 micrometers, used to separate particles from solutions through physical sieving or to sterilize liquids by removing bacteria and microorganisms.
In more detail
Millipore filters work by allowing only molecules and particles smaller than the specified pore size to pass through. They are manufactured from materials such as polycarbonate, cellulose acetate, polyethersulfone (PES), or polyvinylidene fluoride (PVDF), depending on the chemical compatibility required. A 0.2 micrometer pore size is standard for sterilization, effectively removing bacteria from solutions without heat damage. Although Millipore is a brand name (now owned by Merck), the term has become widely used generically in laboratories for this class of membrane filter.
Key facts
| Field | Analytical Chemistry |
|---|---|
| Typical pore sizes | 0.025 to 10 micrometers |
| Standard sterilization pore size | 0.2 micrometers |
| Primary applications | Sterilization, particle separation, sample clarification |
A pharmaceutical company sterilizes an antibiotic solution by passing it through a 0.2 micrometer Millipore filter to remove bacteria before formulating the final drug product, avoiding heat exposure that would degrade the active compound.
Frequently asked questions
How does a 0.2 micrometer Millipore filter sterilize a solution?
It removes bacteria and other microorganisms through physical size exclusion - particles and cells larger than 0.2 micrometers cannot pass through the pores.
Can I use the same Millipore filter for different solvents?
The filter material must be compatible with the solvent - for example, cellulose acetate filters work with aqueous solutions but may dissolve in strong organic solvents, whereas PVDF filters are more chemically resistant.