The early fluidic and optical physics of cytometry
Open Access
- 15 February 1999
Abstract
All forms of cytometry, depend on the basic laws of physics, including those of fluidics, optics, and electronics, most of which were established centuries ago. Flow cytometry depends critically on the fluidics presenting each individual cell with precision to the sensing volume. This is intersected by a high‐intensity light source, and light scattering and fluorescence from suitably stained constituents in each cell are captured by the light‐collecting optics and measured. The works and observations of Bernoulli and Euler in the 18th century, Reynolds in the 19th century, and Crosland‐Taylor in the 20th century in the field of fluid dynamics laid the foundations for hydrodynamic focussing, which is the primary prerequisite for presenting individual cells to the sensing volume. In addition, electrostatic cell sorters must have the ability to generate stable droplet formation in the jet‐stream issuing from the flow chamber nozzle. The origins here can be traced to work carried out in the early to mid‐19th century by Savart, Magnus, and Thomson. Flow, image, and confocal cytometry are all dependent on the laws of optics, including those of reflection and refraction as well as numerous other optical principles. The observations and works of Socrates, Ptolemy, Snel, and Descartes between about bc 370 and 1637 were of seminal importance in developing the laws of reflection and refraction. In the mid‐17th century Hooke illustrated the power of magnifying glasses and microscopy in his Micrographia and Newton was responsible for explaining colours in the spectrum. Huygens, toward the end of the 17th century, put forward the concept of point source light propagation contributing to a wave front. Finally, Thomas Young, early in the 19th century, established the wave form of light from interference patterns. Most people will be familiar with some of these discoveries and the investigators who carried out the work; some people will be familiar with all of these. However, very few people are likely to have had the opportunity and privilege to access the very early works and the original data and manuscripts, or translations thereof, which laid the foundations of physics that enabled our discipline to be established. It is always important for any discipline to remember its roots and to appreciate the seed from which those roots grew, for it is much easier to learn and fully understand when we have a knowledge of the source and the logical progressions that lead from one discovery to the next. This knowledge lends perspective to our current endeavours as the past, after all, created the present, which in turn contributes to the future. In this article, which was presented as an invited lecture at the 9th Canadian Consensus meeting on AIDS, I have attempted to trace the origins of the early work on the physics of fluidics and optics, which laid the foundations. Cytometry (Comm. Clin. Cytometry) 38:2–14, 1999.Keywords
This publication has 15 references indexed in Scilit:
- Optics from Euclid to HuygensApplied Optics, 1966
- High Frequency Recording with Electrostatically Deflected Ink JetsReview of Scientific Instruments, 1965
- Axial Migration of Particles in Poiseuille FlowNature, 1961
- A Device for Counting Small Particles suspended in a Fluid through a TubeNature, 1953
- III. An experimental investigation of the circumstances which determine whether the motion of water shall be direct or sinuous, and of the law of resistance in parallel channelsProceedings of the Royal Society of London, 1883
- XXIX. An experimental investigation of the circumstances which determine whether the motion of water shall be direct or sinuous, and of the law of resistance in parallel channelsPhilosophical Transactions of the Royal Society of London, 1883
- XVI. On a self-acting apparatus for multiplying and maintaining electric charges, with applications to illustrate the voltaic theoryProceedings of the Royal Society of London, 1868
- I. The Bakerian Lecture. Experiments and calculations relative to physical opticsPhilosophical Transactions of the Royal Society of London, 1804
- II. The Bakerian Lecture. On the theory of light and coloursPhilosophical Transactions of the Royal Society of London, 1802
- A letter of Mr. Isaac Newton, Professor of the Mathematicks in the University of Cambridge; containing his new theory about light and colors: sent by the author to the publisher from Cambridge, Febr. 6. 1671/72; in order to be communicated to the R. SocietyPhilosophical Transactions of the Royal Society of London, 1672