Related Experiment Video
Updated: Jun 19, 2026
08:04
Visualizing the Early Stages of Phagocytosis
Published on: February 3, 2017
THE PHAGOCYTOSIS OF SOLID PARTICLES : IV. CARBON AND QUARTZ IN SOLUTIONS OF VARYING ACIDITY
1Laboratories of Physiology, Harvard Medical School, Boston.
The Journal of General Physiology
|October 30, 2009
Summary
Leucocytes, or white blood cells, show varied particle ingestion based on pH and particle type. Manganese dioxide particles are rapidly ingested and attract leucocytes, unlike carbon or quartz.
Area of Science:
- Cell Biology
- Biophysics
- Materials Science
Background:
- Phagocytosis is a critical cellular process involving the engulfment of particles by cells, particularly leucocytes.
- The interaction between leucocytes and particulate matter is influenced by various factors, including particle properties and environmental conditions.
- Understanding these interactions is crucial for fields ranging from immunology to toxicology.
Purpose of the Study:
- To investigate the differential ingestion rates of various particles by leucocytes under different pH conditions.
- To explore the role of particle properties, such as material composition, size, and surface charge, in leucocyte phagocytosis.
- To determine if particle attraction plays a role in the phagocytic process.
Main Methods:
- Comparative analysis of leucocyte ingestion of quartz, carbon, manganese dioxide, and Penicillium spores.
- Experiments conducted in both acidic and alkaline solutions to assess pH-dependent ingestion.
- Observation of leucocyte attraction towards different particle types.
- Investigation of particle size effects on ingestion rates.
- Measurement of electrode potentials and cataphoretic charges to correlate with ingestion.
Main Results:
- Leucocytes ingested carbon particles more readily than quartz in alkaline solutions, and quartz more readily than carbon in acidic solutions.
- Acacia presence favored carbon ingestion over quartz, irrespective of pH.
- Manganese dioxide particles were ingested rapidly and exhibited distinct attraction to leucocytes, unlike quartz or carbon.
- Smaller quartz particles (1 micron) were ingested less readily than larger ones, suggesting factors beyond surface tension.
- Electrode potentials and cataphoretic charges did not fully explain pH-dependent ingestion variations of carbon and quartz.
Conclusions:
- Leucocyte particle ingestion is significantly influenced by solution pH and particle material.
- Manganese dioxide possesses unique properties that enhance its phagocytosis and attract leucocytes.
- Factors beyond simple surface tension and charge influence the phagocytic recognition and engulfment of particles, especially at the microscale.
Related Concept Videos
00:41Phagocytosis
Cells pull particles inward and engulf them in spherical vesicles in an energy-requiring process called endocytosis. Phagocytosis ("cellular eating") is one of three major types of endocytosis. Cells use phagocytosis to take in large objects, such as other cells (or their debris), bacteria, and even viruses.
The objective of phagocytosis is often destruction. Cells use phagocytosis to eliminate unwelcome visitors, like pathogens (e.g., viruses and bacteria). Many immune system cells, including...
The objective of phagocytosis is often destruction. Cells use phagocytosis to eliminate unwelcome visitors, like pathogens (e.g., viruses and bacteria). Many immune system cells, including...
00:41Phagocytosis
Cells pull particles inward and engulf them in spherical vesicles in an energy-requiring process called endocytosis. Phagocytosis (“cellular eating”) is one of three major types of endocytosis. Cells use phagocytosis to take in large objects—such as other cells (or their debris), bacteria, and even viruses.The objective of phagocytosis is often destruction. Cells use phagocytosis to eliminate unwelcome visitors, like pathogens (e.g., viruses and bacteria). It is perhaps unsurprising, that many...
01:17Phagocytosis of Apoptotic Cells
Cells undergoing apoptosis form apoptotic bodies that must be removed immediately to prevent inflammation, autoimmune diseases, and necrosis. Phagocytosis is carried out by professional phagocytes such as macrophages or immature dendritic cells. Non-professional phagocytes such as epithelial cells and fibroblasts also take part in this process; however, they are not as effective as professional phagocytes.
Normal cells contain receptors that prevent them from being recognized by phagocytes.
Normal cells contain receptors that prevent them from being recognized by phagocytes.
01:09Colloidal precipitates
The high insolubility of some precipitates can result in an unfavorable relative supersaturation. This can lead to colloidal particles with a large surface-to-mass ratio, where adsorption is promoted. For instance, in the precipitation of silver chloride, silver ions are adsorbed on the surface of the colloidal particles, forming a primary layer. This layer attracts ions of opposite charge (such as nitrate ions), forming a diffuse secondary layer of adsorbed ions. This electric double layer...
01:29The Colloidal State
The formation of a colloidal system is exemplified by an aqueous solution containing Cl− ions is introduced to another containing Ag+ ions, resulting in the precipitation of solid AgCl as extremely tiny crystals. Instead of settling out as a filterable precipitate, these crystals remain suspended in the liquid, showcasing a colloidal system.A colloidal system involves colloidal particles within the approximate range of 1 to 1000 nm in at least one dimension, dispersed in a medium called the...
01:16Precipitate Formation and Particle Size Control
In precipitation gravimetry, the precipitating agent should react specifically or selectively with the analyte. While a specific reagent reacts with the analyte alone, a selective reagent can react with a limited number of chemical species.
The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability...
The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability...