What is a Phagocytosis Assay?

Article Details
  • Written By: Mary McMahon
  • Edited By: Kristen Osborne
  • Last Modified Date: 19 March 2018
  • Copyright Protected:
    Conjecture Corporation
  • Print this Article
Free Widgets for your Site/Blog


A phagocytosis assay is a laboratory test designed to assess the function of specialized immune cells known as macrophages. There are a number of types of phagocytosis assay used in the lab, including both commercially available tests and tests custom developed for specific labs or experiments. In this test, a collection of macrophages is made and cultured before being exposed to particulate material to see how many cells engulf particles and how quickly they operate. This test has a number of applications.

Macrophages are an important part of the immune system. They work by engulfing particles of material encountered in the body, acting like a cleaning service to clear out infectious agents, the remainders of infections, and any foreign materials. In a person with a strong immune system, these cells will be highly active. In a weakened immune system, there are fewer macrophages and they are less functional. The phagocytosis assay provides information about how active the cells are in the body.

The cells are introduced to a culture with a foreign material inoculated with something that can be used as a tracer. Commonly, fluorescent tags are attached to the material, allowing people to observe macrophage activity under a microscope in specialized lighting. When phagocytic activity is high and the cells work quickly to engulf material, it is indicative of a strong and aggressive immune system. People can also examine how the cells respond to particular types of materials, as for example when testing the efficacy of vaccines.


A number of things can impact macrophage activity and alter the results of a phagocytosis assay. Medications can boost or undermine immune function, and people also respond to environmental factors like exposure to disease and allergens. Vaccinations can teach the immune system to recognize specific antigens, and in a phagocytosis array, the level of macrophage response can be quantified to study a vaccine. If a vaccine works poorly, the cells will not be very active, indicating that the inoculated patient is not safe from disease.

As with other lab tests, the system used for performing a phagocytosis array is standardized and people are expected to follow a lab manual or the directions on a particular test product. This is intended to make test results repeatable while also carefully controlling quality. Samples have to be handled with care to avoid contamination and all observations made during the phagocytosis assay are noted, as they may provide important information usable in repeats of the test or future studies.


You might also Like


Discuss this Article

Post 3

My dad is a researcher, he works in a lab but also does some independent research from time to time. He buys phagocytosis assay kits all the time for his research.

I've seen them before, it's a kit with various testing materials, vials and a set of directions and resources for carrying it out. Of course, he has to use his own microscope and some other things. It's also illegal to use the kit for anything other than research but it's a pretty neat way for scientists to carry out research on their own and study phagocytosis I think.

Post 2

@feruze-- I think you're talking about something else.

Of course, people will react differently to vaccines. The purpose of phagocytosis assay is not to predict the reaction of different people's immune systems to a vaccine. It's simply to see if the vaccine works or not. If the macrophages pick up the virus and produce antibodies for it, then scientists will know that the vaccine is working.

Phagocytosis assays are so important. We would be unable to make vaccines without it and many treatable diseases would be taking lives. I just read an article about a malaria vaccine being developed specifically for mothers-to-be in places where malaria is widespread, like Africa and India. Scientists have been doing phagocytosis assays to see if the vaccine is going to work.

Considering that no one is harmed or used for this kind of testing, phagocytosis assays are like a boon for the medical field.

Post 1

How well does a phagocytosis assay work for testing vaccines when we know that everyone's immune system is different and works at varying strength?

From what I understand, a vaccine is most effective when the person who receives it has enough macrophages that function, right? Because then, the macrophages learn about that virus and will be able to recognize it and kill it quickly if it ever enters the body again.

But if someone doesn't have enough macrophages, it won't be able to do that and the vaccine will basically be useless like the article said.

What's the point of doing a macrophage phagocytosis assay for vaccines if we can't generalize the findings for all people then?

Post your comments

Post Anonymously


forgot password?