How do we choose to go for particular manufacturer while selecting certain testing accessories/ requirements . Like there are many manufacturer of BET LAL reagents , also for membrane filter manufacturer how do we decide which one to choose even if both products are almost renowned and cost factor is same .
Please caryy out validation (or verification) of analytical / testing method using the proposed reagent or membrane filter. Based on validation results, if it meets acceptance criteria then the reagent from that manufacturer can be purchased. Of coure, commercial aspects should also be considered when finalizing the manufacturer to purchase reagents or mambrane filters.
First draft your User Requirement Specification and select the suppliers that meet your URS (supplier requirements: do they have complaints/recall procedure, do they have a certified quality system etc.)
Based on the above and maybe supplier contact at your site, choose the supplier.
This is done BEFORE validation, in order to reduce chance of failed validation