CEO Peter Egelberg comments the recent special issue of Cytometry part A and its importance to PHI and medical science in general.

Cytometry part A is the official journal of the International Society for Advancement of Cytometry (ISAC). The journal publishes original research articles related to cell measurement and analysis. Occasionally special issues are published, covering novel and hot topics of particular interest.


Continual change is a hallmark of life. Our lives as multicellular organisms are the collective results of billions of tiny cell lives that are born, that grow, interact, reproduce and finally die, just like we do. Cytometry is the quanti­tative analysis of these tiny lives.

Leap of understanding

As a layman (swe: lekman), it is natural to assume that cell biologists already have the tools to observe and quantify how these tiny lives play out over time. However, this is not the case.

Traditionally, cells are killed (“fixated”) before they are observed. Cells are increasingly being observed alive. But, these live cell imaging methods rely on that the cells are either genetically modified or “labeled” with toxic fluorescent stains, affecting cell behavior. These and other practical limitations have forced scientists to study the life of individual cells by interpreting a few snapshot images.

We realize how difficult and misleading it can be to comprehend a life from snapshots when we look at the few pictures our grandparents left behind. Obviously, our understanding of their lives would have been dramatically more true and complete, if we instead had the opportunity to watch a movie of their entire lives, secretly recorded to not affect their behavior.

A similar leap (swe: språng) of under­standing is what label-free time-lapse cytometry offers to medical science, and is what motivates this recent special issue of Cytometry part A:

“Quantitative phase imaging [label-free time-lapse cytometry] is a valuable method for studying live cell dynamics, as it provides a noninvasive analysis over a wide range of time scales. This type of analysis is gaining traction very rapidly because it is performed with little to no phototoxicity and requires minimal sample preparation.”

As water waves move slower in more shallow water, beaches phase shift (swe: fasförskjuter) and bend water waves (above image).

In a similar fashion, light waves bend when they travel through more optically dense material. Like tiny glass lenses, cultured cells phase shift and bend an illuminating light wave, as they are optically denser than the surrounding cell culture media.

Quantitative phase imaging is the collective term for holographic and other imaging techniques which create images by measuring how much objects phase shift and bend light.

HoloMonitor in the special issue

In the special issue May of Cytometry part A, various applications of quantitative phase imaging and label-free time-lapse cytometry are presented in a number of scientific articles. HoloMonitor is featured in three articles by scientists at North­eastern University, Boston Children’s Hospital and by our scientists at PHI:

The promise

The special issue and the increasing number of scientific publications by HoloMonitor customers, and others, leave no room for doubt. Label-free time-lapse cytometry has begun to fulfill its promise to medical science — a leap of understanding.

The cover of the special issue. This year the annual CYTO conference, organized by the International Society for Advancement of Cytometry, will be held in Boston.