Guidelines for Efficient Cell Sorting – Part 1

Flow cytometry is a pervasive tool to characterize just about anything in cell biology. From quantifying the expression of surface antigens, to determining the physiological changes in cells and everything in between, flow cytometry is as indispensable to a cell biologist as a knife is to a surgeon. Cell sorting is pivotal in enabling researchers…

reagents

How to Store Your Reagents, so They ‘Do Exactly What It Says on the Tin’

Your reagents should do ‘Exactly what they say on the tin.’  This only happens though if you look after them in the way the manufacturer states on their data sheets. We have all been guilty of using reagents past their expiration date.  Usually we can get away with it, but there are a few things…

Are Quantum Dots Any Good for Flow Cytometry?

Are Quantum Dots Any Good for Flow Cytometry?

What Are Quantum Dots? Quantum dots were discovered in the early 1980s. However, it was not until the late 1990s that their use in biological applications was suggested.1 Quantum dots are semiconducting nanocrystals made of artificial atom clusters. Their size generally ranges from 2 to 20 nm. Size is crucial for their physical properties because…

How to perform cell synchronization in specific cell cycle phases

How to perform cell synchronization in specific cell cycle phases

The cell cycle has been very well documented over the years because of its dysregulation in diseases such as cancer. Many different processes contribute to cell growth and replication, which is ultimately controlled by a series of tightly controlled cell cycle phases. For some areas of research, especially within drug discovery and cancer research, cell synchronization in…

Demystifying the Flow Cytometry Optics System:  A Peek Under the Hood

Demystifying the Flow Cytometry Optics System: A Peek Under the Hood

To many users, the flow cytometer is a magic box: put in cells, get out data. You click the button to tell it which colors to look at without much thought about how the machine does this. However, not all fluorophores are created equal—some configurations might exclude the spectrum you’re really looking for. Here’s a…

Corralling Your Cells: How to Gate in Flow Cytometry

Flow cytometry. Some people love it—most hate it—but all can agree that it is one of the most powerful analytical tools immunologists possess. Here’s a quick refresher: as the name suggests, flow cytometry measures the physical and chemical characteristics of cells. This is accomplished by fluorescently labeling cell surface markers/proteins using antibodies conjugated to fluorophores….

fluorophores

Lighting the Way: Understanding Flow Cytometry Fluorophores

As science is becoming more interdisciplinary, the tools we use to answer questions are also crossing party lines. Case in point: flow cytometry. Once a tool only used by “real” immunologists, flow cytometry is fast becoming a method by which numerous questions can be answered, from the length of a cell’s telomeres, to the state…

Detection of Apoptosis by Flow Cytometry: To Be or Not to Be

Detection of Apoptosis by Flow Cytometry: To Be or Not to Be

Sometimes only a small subset of a cell population will show apoptotic features making flow cytometry an excellent way to identify and quantify them. A previous Bitesize Bio article showed how flow cytometry can detect apoptotic hallmarks. More than 30 different dyes can be used to detect apoptosis. It is also true to say that…

flow cytometry data

How to Destroy your Flow Cytometry Data in 3 Easy Steps: Snap, Crackle, and Pop

While many scientists are methodical and precise, some of us like to live on the edge. Read a protocol all the way through? No thanks, I’ll take my chances and guess what concentration of HCl I should use. Label my tubes with the correct content? Puh-lease – it’s much more exciting deducing which is which…

apoptosis assays
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Flow Cytometric Apoptosis Assays for Cell Death

Apoptosis, often called programmed cell death, is a carefully regulated process that is part of normal development and homeostasis. Apoptosis is morphologically and biochemically distinct from necrosis, which is conversely called accidental cell death. Dysregulation of apoptosis is implicated in disease states such as cancer, autoimmune disease and degenerative conditions. Apoptosis consists of an orderly…

Spot the Difference: 5 Ways to Improve the Presentation of Your Flow Cytometry Data

Take a look at the dotplot below, are you happy with the way it’s presented? Do you think that you could recreate that experiment? If you were a reviewer, would you accept that figure? Sure, it’s flow plot, it shows 3 populations of which two are gated. Read many journals and you will see data…

An Introduction to Spectral Overlap and Compensation Protocols in Flow Cytometry

It strikes fear into the hearts of new cytometrists. Compensation. More fights have started over the proper way to compensate at meetings than anything else. This article will strive to shed some light on the principles of compensation, and equip you with the tools necessary to achieve compensation mastery for your research experiments. Compensation is…

The Exciting (and Emitting) World of Fluorescence

Flow cytometry is a fluorescence-based technology, as is fluorescence microscopy and confocal microscopy. Fluorescence is fundamental to how a cytometer gathers data, but I am often surprised, as a core manager, at how little new users know about the process of fluorescence. So, this is where I always start the training process. Let’s get physical…

Catching Greatness: Measuring Cellular Degranulation

One of the key characteristics of cytotoxic cells (i.e. CD8+ T cells, natural killer cells) is the presence of pre-formed cytoplasmic lysosomal granules. These structures house perforin and granzyme; two molecules that are essential for the lysis of target cells. Upon effector cell activation, granules are polarized toward the target cell and the contents are…

Gateway to the Cellular Kingdom: Cell Fixation and Permeabilization Techniques

One of the much sought after question asked by many researchers worldwide is – “What is the gene expression profile of a single cell within a heterogenous pool of cells?” While mass cytometry is the current ‘hot’ methodology for single cell analysis, the good old flow cytometry can help us perform rapid analysis of single…

Locating Your Cellular Apoptosis Squad: Annexin V Staining Assays

In real life, cells are instructed to commit suicide for the greater good of the organism. The programmed cell death (apoptosis) is important during development of a multi-cellular organism. A good example you will appreciate is the dis-appreance of the tail from a tadpole as it turns into a frog. On the reverse, the lack…

Basic Parameters Measured by a Flow Cytometer: What is Scattered Light and Absolute Fluorescence?

In a previous article, we went over the basic understanding of the inner workings of a flow cytometer. It’s important to grasp the types of measurements that are being made and, perhaps more importantly, what measurements are NOT being made. For simplicity’s sake, we’re going to frame this discussion in terms of a classical flow…

Being “Accuri-te” Through Cytometry: A Guide to Accuri C6 Software

A new lab toy to make it big in the last 5–10 years is the Accuri C6 cytometer (now under the BD umbrella), a low-cost instrument in comparison to the big boys. Lightweight, with a small footprint and straightforward maintenance, it’s often the cytometer of choice. It may be suitable for those labs that require…