Optical Detection Methods for High-Throughput Fluorescent Droplet Microflow Cytometry

High-throughput microflow cytometry has become a focal point of research in recent years. In particular, droplet microflow cytometry (DMFC) enables the analysis of cells reacting to different stimuli in chemical isolation due to each droplet acting as an isolated microreactor. Furthermore, at high flow rates, the droplets allow massive parallelization, further increasing the throughput of droplets. However, this novel methodology poses unique challenges related to commonly used fluorometry and fluorescent microscopy techniques. We review the optical sensor technology and light sources applicable to DMFC, as well as analyze the challenges and advantages of each option, primarily focusing on electronics. An analysis of low-cost and/or sufficiently compact systems that can be incorporated into portable devices is also presented.

[Laser microdissection applications in histology: an open way to molecular studies]

One of the most fascinating aspects of the use of a laser beam in the field of biology has emerged with the development of devices able to perform fine dissections of biological tissues. Laser microdissection can collect phenotypically identical cells from tissue regions laid on a microscope slide in order to make differential molecular analyses on these microdissected cells. Laser microdissection can be used many areas including oncology to specify molecular mechanisms that enable to adapt a treatment related to diagnosis and research in biology, but also forensic science for tissue selection, neurology for post-mortem studies on patients with Alzheimer's disease, for clonality studies from cell cultures and cytogenetics to decipher chromosomal rearrangements. This technology represents the missing link between clinical observations and the intrinsic physiological mechanisms of biological tissues and its major applications will be addressed here.

Study of drug diffusion rate by laser beam deflection technique

Drug administration is an unavoidable part of treatment. When a drug is administered orally or intravenously, it gets absorbed into the blood stream. The rate and efficiency of absorption depend on the route of administration. When a drug is administered through the oral route, it penetrates the epithelial cells of the intestinal mucosa. The diffusion of the drug into the blood stream depends on various parameters, such as concentration, temperature, and the nature of the mucous membrane. The passive diffusion of drugs is found to obey Fick’s law. Water soluble drugs penetrate the cell membrane through aqueous channel or pores. Hence, the study of diffusion of drugs into the water and finally into the blood stream is important. An attempt has been made to study the diffusion of the drug in water as 60% to 80% of human body is water. For the study of drug diffusion in water, a commonly used cough syrup of specific gravity 1.263 is used. It is found that the diffusion rate increases with the concentration of the drug.