Fluorescence Value Decreasing Over Time (Nucleic Acid Quantification)

Question

Accepted Answer

Qubit Fluorometer reading decreases when taking multiple measurements or reading after extended time Common causes: 1) Insufficient incubation time before first reading 2) Tube heating up inside instrument during multiple readings 3) Reading taken more than 3 hours after mixing with dye 4) Standards or samples exposed to light between readings 5) Temperature increase affecting fluorescence signal Solutions: 1) Wait full 2 minutes incubation before reading (15 minutes for protein assays) 2) Remove tube from instrument between multiple readings 3) Allow tube to equilibrate to room temperature for at least 30 seconds before rereading 4) Read samples within 3 hours of mixing with dye 5) Keep standards and sample tubes protected from light between readings 6) Store prepared samples in dark until measurement