Docfan Academy

A reagent that has been stored wrongly may still look perfect and still give a wrong result. You cannot see damage with your eyes, so you must control storage with habits and records.

Read the insert first

Every kit comes with an insert (instructions for use). Before you use a new kit, read what it says about storage, preparation, how long it keeps after opening, and what to do with it. The insert beats memory and beats "we always did it this way".

• 2 to 8 °C means refrigerator. Room temperature is usually about 15 to 25 °C, but some labels say "below 25 °C" or "below 30 °C". Follow the label.
• Do not freeze reagents unless the insert says so. Freezing can damage them even after they thaw and look normal.
• Keep reagents away from direct sun, heat and damp.
• Write the date opened on the bottle, and the date it must be discarded if the insert gives a shorter life after opening.

Lots and expiry

A lot is one production batch. Do not mix reagents, buffers or controls from different lots of the same kit, and never top up an old bottle with new liquid. Use the earliest expiry first (first-expiry-first-out). Never use a reagent after its expiry date, even if "it looks fine".

The reagent log and the reagent fridge

• Keep a log for each kit or reagent: date received, lot, expiry date, date opened, who opened it, and storage checks.
• Put a thermometer in the reagent fridge and record the temperature every working day.
• Use that fridge for reagents only. Food, drinks and personal items do not belong in it. A fridge that is opened for lunch loses its temperature and can be contaminated.