Reagents Prepared by Others Never blindly trust a reagent prepared by someone other than yourself, especially for critical assays. It's a lot like packing your own parachute-it's your responsibility to prepare your important solutions. If you want to trust the outcome of an important experi ment to something someone else may have prepared while think ing about an upcoming vacation, it's up to you. Prepare critical solutions yourself until you have a solid working relationship with whomever you plan to share solutions with. Even then, don't get offended if they don' t trust your solutions! Reagents Previously Prepared by you How reliable are your solutions? Your solutions are probabl fine to use if Your labeling and record-keeping are contemporary and You don't share solutions with anyone who could have mis handled and contaminated them Your material is within it's expected shelf life. What Are Your Options for Storing Reagents? Storage is half the battle(handling is the other half)in keeping reagents fit for use. Follow the manufacturers recommendations. Shelf (r Solids, like buffer salts bottles. Sometimes it is appropriate(e.g, for hygroscopic materi als)to store them in a dessicator on a shelf. Many nonflammable liquid reagents can be also stored on a shelf. Care should be taken to store income micals separately. For example, store acids and bases separated; store strong oxidizers away from other organIcs Vented flammables cabinet Flammables or reagents with harmful vapors(e. g, methylene chloride) should be stored in ventilated cabinets designed for chemical storage. These cabinets are designed to minimize the chance of fire from flammable vapors; they often are designed to contain minor leaks, preventing wider contamination and possible fire. It is a good practice secondary spill cont polypropylene or Teflon trays)in the flammables cabinet if they are not already built into the designReagents Prepared by Others Never blindly trust a reagent prepared by someone other than yourself, especially for critical assays. It’s a lot like packing your own parachute—it’s your responsibility to prepare your important solutions. If you want to trust the outcome of an important experi￾ment to something someone else may have prepared while think￾ing about an upcoming vacation, it’s up to you. Prepare critical solutions yourself until you have a solid working relationship with whomever you plan to share solutions with. Even then, don’t get offended if they don’t trust your solutions! Reagents Previously Prepared by You How reliable are your solutions? Your solutions are probably fine to use if: • Your labeling and record-keeping are contemporary and accurate. • You don’t share solutions with anyone who could have mis￾handled and contaminated them. • Your material is within it’s expected shelf life. What Are Your Options for Storing Reagents? Storage is half the battle (handling is the other half) in keeping reagents fit for use. Follow the manufacturer’s recommendations. Shelf (Room Temperature) Solids, like buffer salts, are usually stored on the shelf in sealed bottles. Sometimes it is appropriate (e.g., for hygroscopic materi￾als) to store them in a dessicator on a shelf. Many nonflammable liquid reagents can be also stored on a shelf. Care should be taken to store incompatible chemicals separately. For example, store acids and bases separated; store strong oxidizers away from other organics. Vented Flammables Cabinet Flammables or reagents with harmful vapors (e.g., methylene chloride) should be stored in ventilated cabinets designed for chemical storage. These cabinets are designed to minimize the chance of fire from flammable vapors; they often are designed to contain minor leaks, preventing wider contamination and possible fire. It is a good practice to use secondary spill containers (e.g., polypropylene or TeflonTM trays) in the flammables cabinet if they are not already built into the design. 40 Pfannkoch