Tech Tips and Protocols
Practical advice and lab tips from Biotium scientists on using fluorescence in your research
Tech Tip: Cell Surface Stains for Live & Fixed Cells
Membrane staining is very useful in defining cell boundaries in multicolor imaging studies. Researchers are ever looking for suitable dyes to use under various viability, fixation and experimental staining conditions dictated by their particular workflow or application. Biotium offers a large selection of highly fluorescent and photostable stains to visualize cell boundaries and morphology in multicolor staining experiments. To select the cell surface stain that is right for you, read about the different types of stains below, and consult the selection table at the end of the page.
Tech Tip: Eight things to keep in mind for optimal gel staining with GelRed® and GelGreen®
The most common use of GelRed® and GelGreen® nucleic acid stains is in pre-cast agarose gels, where the dyes are added to molten agarose during gel preparation. However, due to their larger size designed to improve safety, band migration of DNA in pre-cast gels may be affected. Some samples, such as restriction digested DNA can migrate abnormally in GelRed or GelGreen precast gels.
Tech Tip: Using ViaFluor® SE Stains for Cell Tracing and Co-Culture
ViaFluor® SE Cell Proliferation Dyes were developed for counting cell divisions by flow cytometry. But they also work well for tracing cell morphology, tracking cells over time, and monitoring different populations in co-culture. The dyes are non-toxic, and can be fixed and permeabilized for IF staining. See some workflow examples for different applications here.
Tech tip: Imaging Bacteria Using Agarose Pads
Bacteria can be more difficult to image than other cell types because they are small, usually non-adherent, and are often motile. Here we describe how to image live or fixed bacteria using agarose pads to immobilize the cells during the imaging process, allowing you to perform multi-color fluorescence microscopy experiments.
Tech Tip: Battling Tissue Autofluorescence
Autofluorescence in tissues from lipofuscin, red blood cells, and extracellular matrix can make it all but impossible to distinguish specific fluorescence staining from non-specific background. See our protocols for quenching autofluorescence with TrueBlack®.
Tech tip: Avoiding Artifacts from UV Photoconversion of DAPI and Hoechst
In multi-color imaging experiments, limiting cross-talk between detection channels is crucial for obtaining specific results. Many researchers are unaware that photoconversion of DAPI and Hoechst can cause nuclear stains to bleed into the FITC and Cy®3 channels. Learn about the different ways to avoid it.
Tech Tip: Multi-Color Fluorescence Imaging Using Biotium’s Tyramide Amplification Kits
Tyramide signal amplification (TSA) is an immunofluorescence technique that uses enzymatic coupling to label targets with large amounts of dye, resulting in dramatically higher signal. Here, we provide protocols for performing multiple TSA reactions on the same sample.
Multicolor staining using fluorescent secondary antibodies provides signal amplification for greater sensitivity, but requires that primary antibodies be raised in different hosts. Directly labeled primaries from the same host can used simultaneously, but signal can suffer. A combination of indirect and direct methods takes advantage of the best of both for added flexibility in multicolor staining. See our protocol to learn more.
Protocols for Antibody-Based Detection
Commonly used protocols for performing immunofluorescence staining for microscopy, flow cytometry, and western blotting.