Flow Cytometry Principle

What is flow cytometry, How does FACS work, how to analyze flow cytometry data

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Flow cytometry is a powerful tool because it allows simultaneous multiparametric analysis of the physical and chemical characteristics of up to thousands of particles per second. This makes it a rapid and quantitative method for analysis and purification of cells in suspension. Using flow, we can determine the phenotype and function and even sort live cells.

FACS is an abbreviation for fluorescence-activated cell sorting, which is a flow cytometry technique that further adds a degree of functionality. By utilizing highly specific antibodies labeled with fluorescent conjugates, FACS analysis allows us to simultaneously collect data on, and sort a biological sample by a nearly limitless number of different parameters. Just like in conventional flow cytometry, forward-scatter, side-scatter, and fluorescent signal data are collected. The user defines the parameters on how cells should be sorted and then the machine imposes an electrical charge on each cell so that cells will be sorted by charge (using electromagnets) into separate vessels upon exiting the flow chamber. The technology to physically sort a heterogeneous mixture of cells into different populations is useful for a wide range of scientific fields from research to clinical. Nowadays the terms “flow cytometry” and “FACS” are often used interchangeably to describe this laser-based biophysical technique.

The diagram below illustrates the experimental setup and general procedure of a typical FACS experiment. A population of mixed cells is sorted into a negative sample and a positive sample containing cells of interest by the flow cytometer

What is Flow Cytometry ?

Flow cytometry is a popular cell biology technique that utilizes laser-based technology to count, sort, and profile cells in a heterogeneous fluid mixture. Using a flow cytometer machine, cells or other particles suspended in a liquid stream are passed through a laser light beam in single file fashion, and interaction with the light is measured by an electronic detection apparatus as light scatter and fluorescence intensity. If a fluorescent label, or fluorochrome, is specifically and stoichiometrically bound to a cellular component, the fluorescence intensity will ideally represent the amount of that particular cell component.

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This guide will show you all the nuts and bolts for Flow Cytometry and FACS, including expert review of principle, optimized protocol that really works, and more.

How does flow cytometry work?

Principle overview, The flow cytometer, Forward scatter and side scatter


The number of measurable parameters that can be used by this technology to separate cell populations is immense – starting from simple surface immune-phenotype to metabolic functions, cell cycle status, redox state, and DNA content to name a few. Since its inception, FACS has been used extensively in biomedical research and clinical diagnostics and therapeutics. The most common usage of FACS is seen in:

  • Analysis of whole human blood for diagnosing diseases
  • Sorting different blood cell fractions for ex-vivo manipulations and/or transplantations
  • Immuno-phenotypic analysis of murine blood to identify transgenic/knockout animals
  • Sorting and analysis of a slew of cell lines for various biological assays
  • Characterization and isolation of rare cells types like adult stem cells and cancer initiating cells
How Does Flow Cytometry Works ?

The Flow Cytometer

The flow cytometer instrument consists of three core systems: fluidics, optics, and electronics. The fluidics system includes a flow cell, where the sample fluid is injected. The flow cell requires sheath fluid to carry and align the cells or particles so that they pass through a narrow channel and into the laser intercept (light beam) in a single file. This hydrodynamic focusing allows the analysis of one cell at a time by laser interrogation. The optics system consists of various filters, light detectors, and the light source, which is usually a laser line producing a single wavelength of light at a specific frequency. This is where the particles are passed through at least one laser beam. Lasers are available at different wavelengths ranging from ultraviolet to far-red and have a variable range of power levels as well (photon output/time). Interrogation by the laser beam excites any compatible fluorescent probes that are conjugated to antibodies, causing the probes to emit light (or fluoresce) at specified wavelengths.

The Flow Cytometer Instrument

Forward Scatter Light Signals

Key parameters which are measured by this machine include forward light scatter (FSC), side light scatter (SSC), and fluorescence emission signals. Forward scattered light (FSC) is light that is refracted by a cell in the forward direction, and continues in the same direction that the light was already traveling (typically up to 20° offset from the laser beam's axis). This signal is collected by a PMT called the forward scatter channel (FSC), and is commonly used to determine particle size. Usually, bigger particles will produce more forward scattered light than smaller ones, and larger cells will have a stronger forward scatter signal.

The Flow Cytometer Instrument

Side Scatter Light Signals

Side scattered light (SSC) is light that is refracted by cells and travels in a different direction than its original path (measured at a 90° angle to the excitation line). It usually provides information about the granularity and complexity of the cells. Cells with a low granularity and complexity will produce less side scattered light, while highly granular cells with a high degree of internal complexity (such as neutrophils) will result in a higher side scatter signal. Though it’s affected by shape and size of cells, it’s more sensitive to membranes, cytoplasm, nucleus etc. Thus, by using forward and side scattered light detection, cell populations can often be distinguished based on characteristic differences in cell size and granularity. Both FSC and SSC measurements are influenced by multiple factors and also depends on the quality of sample preparation, thus, to gather more detailed information we could utilize fluorescent labeling techniques with flow cytometr

The Flow Cytometer Instrument

Fluorochromes in Flow cytometry

What roles do Fluorochromes play in flow cytometry, how to choose the right Fluorochromes

Fluorescence and Fluorophore (Fluorochrome) Selection

Cell populations can sometimes be separated based on FSC and SSC, but cells can also be separated by whether they express a specific protein. In this case, a fluorophore is usually used to stain the protein of interest. Fluorophores used for the detection of target proteins emit light after excitation by a laser of compatible wavelength. These fluorescently stained cells or particles can be detected individually. Each type of fluorescent dye or label has its own characteristic excitation and emission spectrum which is important for designing flow cytometry experiments. There is a wide selection of fluorophores available nowadays; for example, FITC, PerCP, APC, PE, Cy5.5, Alexa Fluors, and more. Fluorescently conjugated antibodies have commonly been used to label specific structures on the cell for flow cytometric analysis. As the fluorescing cell (or particle) passes through the interrogation point and interacts with the laser beam, it creates a pulse of photon emission over time (a peak). These are detected by the PMTs and converted by the electronics system to a voltage pulse, typically called an "event". The total pulse height and area is measured by the flow cytometer instrument, and the voltage pulse area will correlate directly to the fluorescence intensity for that individual event. These events are assigned channel numbers based on its measured intensity (pulse area). The higher the fluorescence intensity, the higher the channel number the event is assigned. This signal can be amplified by increasing the voltage running through the PMT.

Fluorescent Light Emission Signals

One thing to note is that fluorescent signals may also occur from naturally fluorescing substances in the cell such as reduced pyridine nucleotides (NAD(P)H) and oxidized flavins (FAD), and this is termed “autofluorescence”. In general, larger and more granular cells have higher levels of autofluorescence due to having an increased amount of fluorescent compounds. The level of autofluorescence can be determined using unstained controls. It is often useful to have an unstained control, or an FMO (Fluorescence Minus One) control. The FMO control will help you to identify and gate cells during data analysis.

Click Here to Learn More About FMO controls
The Flow Cytometer Instrument

Selecting the Right Fluorochrome Conjugate

There are many fluorescent molecules, also known as fluorochromes, fluorophores, or fluorescent dyes, with a potential application in flow cytometry. These fluorescent molecules are excited by laser light at specific wavelengths and then emit light (fluoresce) at another wavelength. By conjugating (pre-attaching) them to primary antibodies, we can create conjugated antibodies that allow for flow cytometry analysis. Knowing each conjugate label’s properties will be important in choosing the right label for your experiment. Some key features to know about fluorescent conjugate tags are listed here:

  • Maximum Excitation Wavelength (λex) – The peak wavelength in the excitation (absorption) spectra, measured in nanometers (nm)
  • Maximum Emission Wavelength (λem) – The peak wavelength in the emission spectra, measured in nanometers (nm)
  • Extinction Coefficient (ε max ) – (also called molar absorptivity) The capacity for the fluorochrome to absorb light at a given wavelength, usually measured at the maximum excitation wavelength with the units M −1 cm −1
  • Fluorescence Quantum Yield (Φf) – The number of photons emitted per absorbed photon. High quantum yield is important, and this number ranges between 0 and 1
  • Fluorescence Decay Time (τfl) – The time interval after which the number of exciting fluorescent molecules is reduced to 1/e (approx. 37%) via the loss of energy, usually measured in nanoseconds
  • Brightness – The fluorescence output per fluorophore measured. Fluorophores with high brightness values can be used to detect lower-abundance targets. Calculated as the product of the extinction coefficient (at the relevant excitation wavelength) and the fluorescence quantum yield divided by 1000, with the units M −1 cm −1
  • Stokes Shift – The difference between the Maximum Emission Wavelength and Maximum Excitation Wavelength, measured in nanometers
  • Laser line – Which laser line(s) to use for detection using flow cytometry
  • Common filter set – The standard microscope filter set that generates the best imaging results
  • Photostability – How resistant a substance is to change resulting from exposure to light

Once you have selected suitable fluorochromes and antibodies for your flow cytometry experiment, the section below will walk you through the general experimental procedure.

Flow cytometry workflow

General experimental procedure

Sample Preparation

The primary requirement for all types of flow cytometric analysis is that the cells under analysis must be in a single-cell suspension. It is very important to obtain a single-cell suspension to avoid clogging up the system with clumps. Peripheral blood mononuclear cells (PBMCs) isolated from whole blood through Ficoll gradient centrifugation, or RBC lysed whole blood, or non-adherent cultured cells are readily applicable for flow cytometric analysis. Adherent cultured cells or cells present in solid organs should first be made into a single cell suspension before flow analysis by using enzymatic digestion or mechanical dissociation of the tissue, respectively. Subsequently, mechanical filtration should be performed to avoid unwanted instrument clogs and obtain higher quality flow data. The cells are then incubated in test tubes or microtiter plates with unlabeled or fluorescently conjugated antibodies and analyzed through the flow cytometer machine.

Click Here for Sample Preparation Guide

Flow antibody staining

*This is a conceptual explanation for how flow cytometry works.

Click here for step-wise flow cytometry protocols.

Antibody Staining

Direct staining

Each human cell expresses hundreds of thousands of cell surface antigens that specify their cell type, biological function, development stage, and more. Cells from different organs have characteristic surface antigens, and we can utilize fluorochrome-conjugated antibodies specific for these surface markers to analyze these cells directly by flow cytometry. In direct immunofluorescence staining, cells are incubated with an antibody directly conjugated to a fluorophore such as PerCP. This requires only one antibody incubation step and therefore eliminates the possibility of non-specific binding from a secondary antibody. Direct staining is advantageous during intracellular staining because large antibody-fluorophore complexes including secondary antibodies can become trapped and result in non-specific binding, or they may fail to enter the cell which results in no detection.

If the experiment will be staining with unconjugated purified antibody, there needs to be an additional step of staining with a fluorescent conjugated secondary antibody (indirect staining).

Click for Direct Staining Protocol

Indirect staining

In indirect staining, the fluorophore conjugated secondary antibody detects the primary antibody which is unconjugated. Another available method is the avidin-biotin system, whereby a biotin-conjugated antibody is detected with fluorophore-labeled avidin. There is a wide range of conjugated antibodies available today, and with indirect staining, the choices of target proteins further increases. Now unconjugated primary antibodies raised against many different targets can be used together with a conjugated secondary antibody for flow cytometric analysis.

Click for Direct Staining Protocol

Intracellular staining

In addition to the cell surface antigens, the intracellular staining procedure allows direct measurement of antigens (cytokines or transcription factors) present inside the cell cytoplasm or nucleus. In this procedure, the fixation and permeabilization of cells are required. Fixing cells will retain the target protein in its original cellular location, and will usually ensure better stability of soluble antigens and antigens with a short half-life. Detecting intracellular antigens requires cell permeabilization before staining, and antibodies should be prepared in permeabilization buffer to ensure the cells remain permeable. This modified staining procedure allows direct measurement of functional activity of any cell of interest present in blood or other tissues without further separation.

Various fixation and permeabilization methods are available to allow access of antibodies to intracellular proteins. To achieve better results, additional in vitro stimulation with some common mitogen may be required to trigger increased production of cytokines inside cells. Some common mitogens for this purpose include PMA, Ca++ or peptide epitopes and protein transport inhibitor, Brefeldin A, etc. Detecting secreted proteins can be difficult if the proteins are released from the cell before detection, or if they degrade rapidly. In these situations, we recommend using Brefeldin A or other compounds that prevent protein release from the Golgi apparatus. A Golgi block such as Brefeldin A will inhibit secretion of expressed proteins from the Golgi apparatus, trapping them in the cell to be detected. The intracellular staining method can then be utilized for detection of the target protein.

Click for Intracellular Staining Protocol

Cell Stimulation, Fixing, and Permeabilization Steps

For more experimental advice, be sure to visit our Optimization Guide by clicking the link below. A successful staining procedure is dependent on optimization of experimental conditions which includes titering of antibodies, optimized fixation and permeabilization procedures, and setting up appropriate controls. Once your samples are prepared as single-cell suspensions and you have all your controls ready, simply run it through the flow cytometer according to the instrument's instructions to obtain your data results. Click here for Optimization Guide

Flow Cytometry Cell Stimulation Fixing and Permeabilization Steps

Data Analysis

In a flow cytometry experiment, every cell that passes through the interrogation point and is detected will be counted as a distinct event. Each type of light that is detected (forward-scatter, side-scatter, and each different wavelength of fluorescence emission) will also have its own unique channel. The data for each event is plotted independently to represent the signal intensity of light detected in each channel for every event. This data could be visually represented in multiple different ways, so you may need to play around with different types of data plots and how to set your gates. The most common types of data graphs used in flow cytometry include histograms, dot plots, density plots, and contour diagrams. As multiparametric analysis becomes more complicated, analysis techniques can even include higher order plots such as 3 dimensional plots and SPADE trees.

Univariate histogram plots measure only one parameter. Typically, the Y-axis is the number of events (the cell count) that show a given fluorescence, and the X-axis is the relative fluorescence intensity detected in a single channel. A large number of events detected at one particular intensity will be represented as a peak (or spike) on the histogram. Ideally, only one distinct peak will be produced and can be interpreted as the positive dataset (representing the cells with the desired characteristics of interest).

Histogram Plot

Oftentimes however, flow analysis is performed on a mixed population of cells and results in multiple peaks on the histogram. In these situations, the flow experiment should be repeated with an appropriate negative isotype control which should help to identify the positive dataset. For a positive result, look for the shift in intensity between negative control and positive samples as shown in the diagram below.

Flow Cytometry Histogram Plot

Isotype Control

For bivariate analysis, data is often represented as dot plots or density plots, and contour diagrams. By analyzing multiple parameters, we can show the relationship between two different markers, allowing for more complex phenotypes to be identified and important populations of interest to be isolated via gating. Gating is an important procedure in flow cytometric data analysis used to selectively visualize the cells of interest and eliminate results from unwanted particles such as dead cells and debris. Click here to learn more about Isotype Controls

Isotype Control

Density Plots

Dot plots and density plots compare 2 or 3 parameters simultaneously on a scatter-plot where each event is represented as a single point (or dot). The dot plot is a figure that shows the relationship between multiple variables at once, and the parameters can be any combination of scatter and fluorescence signals. Three common combinations used are: 1) forward scatter (FSC) vs. side scatter (SSC); 2) single color vs. side scatter; and 3) two-color fluorescence plot.

The density plot was developed as a way to show not just expression levels, but the relative number of events (density) in a given region. On the density plot, each dot or point represents a single cell that has passed through the interrogation point of the flow cytometer. Intensity measurements of different channels are represented along the different axes so that events with similar intensities will cluster together in the same region on the scatter-plot. Density plots are excellent for viewing the frequency of subpopulations.

In this example of a dot-plot, cell populations in a peripheral blood sample can be identified based on forward- and side-scatter light signals. Cell populations are marked by their probable identities:

Image Reference : Riley and Idowu. Principles and Applications of Flow Cytometry.

Image Caption : Dot plot of forward-scatter light vs. side-scatter light. Each dot represents an individual cell analyzed by the flow cytometer. The characteristic position of different cell populations is determined by different physical properties such as cell size and granularity, explained in detail below:

  • Debris: Very small items (such as cellular contaminants) with low forward- and side- scatter.
  • Leukocytes/Monocytes: Small to medium cells with low internal granularity. These cells produce a medium forward-scatter and low side-scatter signal intensity
  • Granulocytes: Large cells with high internal granularity. These cells produce high forward- and side-scatter signal intensities.
flow cytometry contour plot example

Image Caption: Contour diagram of forward-scatter light vs. side-scatter light. Density is represented by contour lines, and like the dot plot, the characteristic position of different cell populations is determined by different physical properties such as cell size and granularity.

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Identifying Cell Populations

As you can see, some cell identities can be confirmed by forward and side-scatter profiles, but fluorescent labeling with a cell-type specific marker will provide greater resolution and certainty when profiling complex heterogeneous cell populations. In the example plot above, one may be able to distinguish between lymphocytes and granulocytes using forward and side-scattered light measurements. However, among the granulocytes there are three different classes (eosinophils, basophils, and neutrophils) which are difficult to distinguish using light-scattering properties alone because of their similar cell size and structure. In order to identify the basophils, for example, we could selectively label them with fluorescently conjugated antibodies which target basophil specific markers.

Contour Plots

The other way to show the density of your data is to use a contour plot. Contour plots display the relative frequency of the populations, regardless of the number of events collected. A contour diagram displays the probability contouring with joined lines representing similar numbers of cells. Concentric rings form around populations so that the higher the density, the closer the rings are on the contour diagram. Thus, this graph takes on the appearance of a geographical altitude map with steeper islands where the density is high. In a 5% contour plot, five percent of cells fall within each contour line (as defined by the plot). Thus, the outermost line contains 95% of the cells; the second line contains 90% and so on. In the example contour plot below, the cell populations which were represented in the density plot example above is now visualized with a contour diagram instead.

One disadvantage of contour plots is that information about rare populations is not visible since these diagrams are not good at showing outliers. In a 5% contour plot, 5% of cells would fall outside of the last contour line. In these situations, some data analysis programs will have the option to add outliers to most graph types. Another strategy is to combine a contour plot with a dot plot, allowing both density estimation and rare event information to be displayed. It is essential to choose the best way to communicate your data to help you convince your peers of the results you are proposing. Be sure to highlight your results by using the right flow figures to accurately reflect your data without confusion.

Popular ELISA kits

Here are the 212 most popular ELISA kits.

TNF Alpha elisa IL6 ELISA Cortisol ELISA VEGF elisa
BDNF elisa IFN Gamma elisa Adiponectin elisa IL-1 Beta elisa
IL10 ELISA IL-8 elisa Leptin elisa IL2 ELISA
IL-12 elisa Granzyme B elisa MPO elisa ADA elisa
APP elisa TGF Beta 1 elisa MAG elisa IL4 ELISA
MMP-9 elisa PLAT elisa Cystatin C elisa CCL2 ELISA
IL-17 elisa PD-L1 elisa APOE elisa NGF elisa
CXCL10 elisa PAI-1 elisa S100B elisa Galectin-3 elisa
EGF elisa Fibronectin elisa GM-CSF elisa MMP-3 elisa
Cortisol elisa Kit Insulin elisa Kit IL33 ELISA GDF-15 elisa
Resistin elisa FGF21 elisa AFP elisa Angiopoietin-2 elisa
Clusterin elisa P53 elisa IDS elisa Ferritin elisa Kit
MMP-1 elisa OPN elisa Endothelin 1 elisa PCSK9 elisa
HGF elisa G-CSF elisa VWF ELISA CXCL1 elisa
PD-1 elisa Caspase 3 elisa TIMP1 ELISA P-Selectin elisa
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IL-15 elisa COMP elisa IL-22 elisa ANG ELISA
CEA elisa Periostin elisa Galectin-9 elisa MMP2 ELISA
TEK ELISA Cathepsin B elisa CXCL5 elisa CXCL9 elisa
VEGFC ELISA CCL17 elisa CXCL13 elisa IL-27 elisa
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M-CSF elisa PLGF elisa RANK elisa Thrombomodulin elisa
MIA elisa HE4 elisa IL7 ELISA PDGF-AB elisa
C-MET elisa IL-1RA elisa Renin elisa FABP2 elisa
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CD163 elisa MICA elisa Progranulin elisa FGF19 elisa
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Tenascin-C elisa IL-32 elisa TFPI ELISA IL18BP ELISA
AXL elisa Aggrecan elisa ALCAM elisa ICAM1 ELISA

Popular Antibodies

Here are the 300 most popular antibodies.

acetylcholinesterase antibody ADAM10 antibody ADAMTS13 antibody adiponectin antibody
AGO2 antibody AHR antibody ALK antibody alkaline phosphatase antibody
AMH antibody ANG antibody annexin a1 antibody APOE antibody
AQP1 antibody aquaporin 4 antibody ARC antibody ATF4 antibody
ATF6 antibody ATM antibody ATRX antibody BAX antibody
bcl xl antibody BCR antibody beclin 1 antibody BRCA1 antibody
CAD antibody calreticulin antibody caspase 1 antibody caspase 8 antibody
catalase antibody cathepsin b antibody Ccl2 antibody CCR4 antibody
CCR5 antibody cd11b antibody cd11c antibody Cd14 antibody
cd16 antibody CD163 antibody CD19 antibody cd2 antibody
cd20 antibody CD200 antibody CD24 antibody CD27 antibody
cd30 antibody CD33 antibody CD34 antibody CD36 antibody
Cd40 antibody CD44 antibody cd45 antibody CD47 antibody
CD63 antibody CD68 antibody cd8 antibody CD80 antibody
CD81 antibody CD86 antibody Cd9 antibody CDK2 antibody
CDK4 antibody ceruloplasmin antibody CHAT antibody claudin 5 antibody
collagen i antibody collagen ii antibody creb antibody Crp antibody
csf antibody CSF1R antibody Ctla4 antibody CXCL10 antibody
CXCR3 antibody CXCR4 antibody cyclin antibody cytokeratin 5 antibody
desmoglein 3 antibody DKK1 antibody DLL4 antibody DNMT1 antibody
doublecortin antibody EEA1 antibody EGFR antibody enos antibody
EPCAM antibody ERBB2 antibody erythropoietin antibody EZH2 antibody
fak antibody FAP antibody FAS antibody FGF21 antibody
Fgf23 antibody FGFR1 antibody FLT3 antibody FOS antibody
FOXO1 antibody FOXP3 antibody GAL antibody GAPDH antibody
GATA3 antibody GDF15 antibody glut4 antibody gp100 antibody
GPI antibody GPX4 antibody grp78 antibody HGF antibody
HIF1A antibody HLA-A antibody hsp90 antibody huntingtin antibody
iba1 antibody ICAM1 antibody Icos antibody IDS antibody
IFNAR1 antibody Igf1r antibody Il10 antibody IL13 antibody
IL15 antibody Il17a antibody IL18 antibody IL1B antibody
IL2 antibody IL33 antibody IL5 antibody IL6R antibody
IL8 antibody inos antibody IRF3 antibody islet 1 antibody
JAK2 antibody jnk antibody KEAP1 antibody KLF4 antibody
L1CAM antibody lactoferrin antibody lamin a antibody LAMP1 antibody
LAT antibody leptin antibody Lif antibody LOX antibody
lysozyme antibody MAG antibody MAX antibody MBP antibody
MDM2 antibody MERTK antibody mesothelin antibody MICA antibody
MIF antibody MLH1 antibody MMP2 antibody MMP9 antibody
MOG antibody MTOR antibody MUC2 antibody myeloperoxidase antibody
NANOG antibody nephrin antibody nestin antibody NGF antibody
NLRP3 antibody NOTCH1 antibody NOX4 antibody NPY antibody
NRP1 antibody occludin antibody osteocalcin antibody osteopontin antibody
p300 antibody p63 antibody parkin antibody parp antibody
PAX6 antibody PAX8 antibody PCSK9 antibody pd l1 antibody
PDGFRA antibody PDGFRB antibody perilipin antibody perk antibody
Pf4 antibody pgp9.5 antibody PML antibody ppar gamma antibody
PROX1 antibody PTEN antibody rab7 antibody RAC1 antibody
RAD51 antibody rea antibody RET antibody rip3 antibody
RIPK1 antibody RUNX2 antibody SHH antibody SIRT1 antibody
SMAD2 antibody smad3 antibody SNAP25 antibody SOD1 antibody
SOD2 antibody somatostatin antibody SOX10 antibody SOX2 antibody
SOX9 antibody SP1 antibody SPR antibody SRC antibody
STAT3 antibody STAT6 antibody survivin antibody SYK antibody
TAZ antibody TBK1 antibody tdt antibody TERT antibody
thrombin antibody Thy1 antibody tim 3 antibody TLR2 antibody
TLR3 antibody TLR4 antibody Tnf antibody topoisomerase i antibody
transferrin antibody trkb antibody TSG101 antibody TSHR antibody
TSLP antibody ubiquitin antibody VDAC1 antibody vegf antibody
VWF antibody XBP1 antibody ZEB2 antibody

Flow Cytometry FAQs

Flow cytometry is a laboratory method used to detect, identify, and count specific cells. This method can also identify particular components within cells. This information is based on physical characteristics and/or markers called antigens on the cell surface or within cells that are unique to that cell type.

Lean Flow is about how items or people we are dealing with in a process move from the first step to the last. Obviously, the intention in Lean flow is to move the item or product through the process as quickly as possible, without any risk to quality and customer satisfaction.