Derek Davies

Derek gained his Bachelor’s Degree in Animal Physiology and Nutrition from the University of Leeds.

Articles by Derek Davies

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…

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…

cell cycle analysis

Cell Cycle Analysis by Flow Cytometry: Flowing your Way through Life’s Cycle

Over the past few decades the mammalian cell cycle has been well documented. Although there are lots of checkpoints as cells move through the cycle, we can very simply divide the cell cycle into three stages according to the DNA content in the nucleus. When cells are either quiescent or not dividing they have the…

Putting Down a Marker in Flow Cytometry to Help Determine Positivity

Putting Down a Marker in Flow Cytometry to Help Determine Positivity

In many biological experiments the question that a researcher wants to ask is – ‘do some or all of my cells express a particular protein?’ There are many ways of doing this, which you will be familiar with e.g. Western blotting, immunoprecipitation, microscopic examination of stained cells and even mass spectrometry. Using Flow Cytometry to…

Using Flow Cytometry for Cell Proliferation Assays: Tips for Success

Using Flow Cytometry for Cell Proliferation Assays: Tips for Success

We all know, generally from bitter experience, that experiments don’t always work first time and that sometimes the little things that govern success are the things that get left out of that online protocol! So whether you are assessing proliferation by nucleotide incorporation or by dye dilution, here are some handy hints to help you…

Cell Proliferation Round 2 And Beyond:  The Dye Dilution Method

Cell Proliferation Round 2 And Beyond: The Dye Dilution Method

Like the legendary fight between boxers Bowen and Burke in 1893, the cell cycle in some cells goes on and on..round 1, round 2, round 3, round 4…before the final bell is rung. Nucleotide analogs, like BrdU or EdU, are great for examining 1-2 cell cycle division(s).  In many studies though, for example the proliferation…

Cell Proliferation Round 1: Using Thymidine Analogs With Flow Cytometry

Cell Proliferation Round 1: Using Thymidine Analogs With Flow Cytometry

Around and around the cell cycle goes, where it stops, nobody knows. Unless you have the right tools to analyze DNA content, that is. The DNA markers propidium iodide, Hoechst and DAPI are commonly used in flow cytometry to analyse a cell’s DNA content.  Although they are simple to use, they do have disadvantages. Figure…