Bioequivalence and Bioavailability Forum

Dear Sajbicz,

❝ We are discussing after yrs of the practice which order in spiking blank plasma is the best.

When spiking large volumes of plasma into a volumetric flask: the usual practice is to half-fill the flask with plasma, add the working solution, mix and make up to the full volume.

When spiking single separate tubes: each approach has its pros and cons. The one positive thing I see in your colleague's approach comes in the case somebody talks to you at the wrong moment, you get distracted and you don't know where you had stopped and which tube has been spiked or not. If you first add the working solution to the tube you immediately see which tube has been spiked. It avoids double spiking or no spiking at all.

Did you ask him why he was doing it this way (apart from "this is how I've always done it and you're not going to teach me my job") ?