Absorbance Repeatability with the Square One Cuvette Holder
Cuvette-based absorbance measurements are only as good as the system used for the measurements. Baseline drift and other spectral changes attributed to varying ambient conditions can be addressed by taking frequent background and reference measurements. Cuvette-to-cuvette variability is overcome using matched cuvettes. Measurement acquisition parameters are set to provide the highest possible signal to noise ratio. So why does your baseline drop below zero when you switch out samples? Why are your absorbance values negative? Why is your standard curve so poorly correlated? The answers may exist in a component of your system you probably don’t even think about – your cuvette holder.
Accurate absorbance data requires a well-engineered cuvette holder that enables users to remove and replace cuvettes repeatably.
Even the most expensive, matched set of quartz cuvettes will not provide accurate data if the cuvettes are not placed consistently into the cuvette holder. Cuvettes should fit snugly in the holder, so they can be removed and replaced without causing a change in spectral data. Baselines that shift below zero and negative absorbance values are immediate warning signs of problems. These issues call the data into question and erode confidence in the results. How can you trust any of the data you just collected when these events happen?