Choosing the best 96-well plate for fluorescence assays: why black ones are the key

Fluorescence measurements are an important topic in the biopharmaceutical industry and used to monitor biological processes or reactions. An easy way to perform these measurements on multiple approaches simultaneously is to use well plates, especially black 96-well plates.

Searching for the right plate

When atoms or molecules absorb light from a specific wavelength, they become excited to a higher energy state. By returning to their ground state, they emit light, which is referred to as fluorescence. Performing fluorescence measurements in the laboratory is a common task and necessary for various assays. Choosing the right equipment for these measurements is essential for the performance of the test. When testing multiple samples simultaneously, well plates are the optimal solution, yet they come in a variety of sizes and designs. It is essential to select the plate that best meets the specific requirements of the assay. For fluorescence measurements, black well plates are the preferred choice, as they minimize light scattering and reflection of the excitation source. This reduction in background interference ensures the most reliable and accurate measurement results.

A black well plate it is, but which one?

In addition to minimizing reflection and light scattering, using black well plates reduces background signal, thereby increasing measurement sensitivity. However, plates with many wells, such as 96-well or 384-well formats, can suffer from “crosstalk,” where light scatters between adjacent wells. The black walls of the plates effectively eliminate this issue.

There are several plate variations to consider. Black well plates are available with either clear bottoms or as fully black plates. Clear-bottom plates allow for bottom reading or microscopic imaging, while the black walls still prevent lateral light scattering. In contrast, fully black plates offer the greatest reduction in background noise and crosstalk, providing the highest sensitivity. The trade-off is that only top reading is possible with these plates.

Once the choice of the bottom format is made, additional factors should be considered. For cell-based assays, surface treatment may be needed to promote cell attachment. Plates can be pre-coated with peptides for specific applications, plasma-treated, or manually coated as needed. Sterility is also essential for cell-based assays, making sterile well plates the preferred option in these cases.

Fluorescence measurements made eco-friendly

Lab work generates enormous amounts of single-use plastic waste, contributing to the estimated 5.5 million tons of lab-related plastic discarded globally each year. It’s a growing challenge the industry can no longer ignore. Most conventional well plates are made from polystyrene, a plastic derived from fossil fuels. Producing polystyrene consumes non-renewable resources and contributes to greenhouse gas emissions. With millions of well plates used every year, the environmental impact of this fossil-based plastic is substantial.

To address this issue, Green Elephant Biotech has developed a fully black 96-well plate made from polylactic acid (PLA), a plant-based, renewable polymer. PLA is produced from raw materials such as corn or sugarcane, significantly reducing dependence on fossil resources. While all laboratory plastics must be properly disposed of - often through incineration - choosing PLA offers a more sustainable option. Compared to conventional polystyrene-based equivalents, it lowers the overall environmental footprint by reducing fossil fuel consumption and greenhouse gas emissions throughout the product’s lifecycle.

The Green Elephant® black 96-well PLA plate is ideal for a wide range of fluorescence measurements. It is currently available in a non-sterile version and can be ordered directly from the Green Elephant Biotech website.