Bioequivalence and Bioavailability Forum

Dear members,

Our lab used to do pipetting analyte into tube first, then adding blank plasma. People liked it because, as you guys mentioned, you can actually see if solution has been added or not. However, there was one project where we had to do the spiking in glass tube sitting in ice-water bath to control temperature. Results were poor especially at low concentration. After many testing to find problem, we were able to conclude that the analyte spiked to glass tube at low temperature adsorbed to glass. Adding plasma first and followed by solution of analyte solved our problem. Now, we only do it in this order with any molecule.

Learned it the hard way,
Ladi