The polymers form separate aqueous phases when mixed at suitable concentrations because they partition differently in water. Cells then distribute between these phases rather than remaining uniformly suspended. Their location reflects combined effects of cell-surface properties, size, density, and interactions with each polymer, allowing researchers to favor one cellular population over others.
Partitioning depends on several cell characteristics acting together. Surface properties affect how cells interact with dextran and PEG, while size and density also influence their distribution. These differences can separate leukocytes, erythrocytes, and other sample components, although the outcome reflects the combined behavior of the cells and polymers rather than a single physical feature.
Polymer concentration is a central condition because it determines whether the mixed solution forms the aqueous two-phase system needed for separation. Once the phases develop, polymer interactions with cells help determine their distribution. Selecting suitable concentrations therefore supports enrichment or removal of targeted populations, while unsuitable conditions may not produce the intended partitioning pattern.
A typical workflow combines the biological sample with dextran and PEG at suitable concentrations, allowing the polymers to form separate aqueous phases. Cells then distribute according to their properties and polymer interactions. The phase containing the desired population can be collected or used for subsequent preparation, producing an enriched or depleted sample for downstream work.
The technique is useful when a complex biological sample contains cellular components that need to be enriched or removed before analysis or culture. In immunology, researchers may use its differing partition behavior to prepare leukocyte-containing fractions or reduce erythrocyte contributions. This preliminary separation can simplify later handling and support studies requiring relatively purified immune-cell populations.
Its gentle operation can help prepare viable cellular populations for downstream assays, while its scalability supports processing of complex samples. Infection researchers can use separated leukocyte, erythrocyte, or other fractions in pathogen-associated cell studies. Preparing the sample before analysis or culture may improve the suitability of the recovered populations for immunological investigation.