Felix MaurerExperimental Physics, Saarland University, Saarbruecken, Germany, Camila RomeroExperimental Physics, Saarland University, Saarbruecken, Germany, Nikolas LerchExperimental Physics, Saarland University, Saarbruecken, Germany, Thomas JohnExperimental Physics, Saarland University, Saarbruecken, Germany, Lars KaestnerExperimental Physics, Saarland University, Saarbruecken, GermanyDepartment of Theoretical Medicine and Biosciences, Saarland University, Homburg, Germany, Christian WagnerExperimental Physics, Saarland University, Saarbruecken, GermanyPhysics and Materials Science Research Unit, University of Luxembourg, Luxembourg, Alexis DarrasExperimental Physics, Saarland University, Saarbruecken, Germany
{"title":"Competing aggregation and iso-density equilibrium lead to band pattern formation in density gradients","authors":"Felix MaurerExperimental Physics, Saarland University, Saarbruecken, Germany, Camila RomeroExperimental Physics, Saarland University, Saarbruecken, Germany, Nikolas LerchExperimental Physics, Saarland University, Saarbruecken, Germany, Thomas JohnExperimental Physics, Saarland University, Saarbruecken, Germany, Lars KaestnerExperimental Physics, Saarland University, Saarbruecken, GermanyDepartment of Theoretical Medicine and Biosciences, Saarland University, Homburg, Germany, Christian WagnerExperimental Physics, Saarland University, Saarbruecken, GermanyPhysics and Materials Science Research Unit, University of Luxembourg, Luxembourg, Alexis DarrasExperimental Physics, Saarland University, Saarbruecken, Germany","doi":"arxiv-2407.07676","DOIUrl":null,"url":null,"abstract":"Centrifugation of erythrocytes (aka Red Blood Cells, RBCs) in a self-forming\nPercoll gradient is a protocol often used as a way to sort RBCs by age.\nHowever, a pattern formation of discrete bands is systematically observed along\nthe continuous density gradient. Although early studies mentioned that\naggregation between cells might modify their spatial distribution, it is\ndebated whether a population with continuous density distribution can form\ndiscrete bands. Here, we develop a continuity equation, considering the\naggregation of cells with a continuous density distribution, which describes\nthe macroscopic evolution of the RBC volume concentration in a density\ngradient. The numerical solutions demonstrate that the competition between\niso-density distribution and aggregation is sufficient to create band patterns.\nOur model reproduces the temporal evolution observed in the conventional\nexperimental protocol, but also predicts several types of bifurcation-like\nbehaviors for the steady-state patterns in constant gradients, when the volume\nfraction and aggregation energy of the cells are varied. We threrefore\ndiscovered that the competition between RBC aggregation and iso-density\ndistribution is a novel physical mechanism leading to pattern formation.","PeriodicalId":501305,"journal":{"name":"arXiv - PHYS - Adaptation and Self-Organizing Systems","volume":"36 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - PHYS - Adaptation and Self-Organizing Systems","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2407.07676","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Centrifugation of erythrocytes (aka Red Blood Cells, RBCs) in a self-forming
Percoll gradient is a protocol often used as a way to sort RBCs by age.
However, a pattern formation of discrete bands is systematically observed along
the continuous density gradient. Although early studies mentioned that
aggregation between cells might modify their spatial distribution, it is
debated whether a population with continuous density distribution can form
discrete bands. Here, we develop a continuity equation, considering the
aggregation of cells with a continuous density distribution, which describes
the macroscopic evolution of the RBC volume concentration in a density
gradient. The numerical solutions demonstrate that the competition between
iso-density distribution and aggregation is sufficient to create band patterns.
Our model reproduces the temporal evolution observed in the conventional
experimental protocol, but also predicts several types of bifurcation-like
behaviors for the steady-state patterns in constant gradients, when the volume
fraction and aggregation energy of the cells are varied. We threrefore
discovered that the competition between RBC aggregation and iso-density
distribution is a novel physical mechanism leading to pattern formation.