Biological sample preparation for various bioassays, Microfluidic cell sorting
Why does sample preparation matter and How do we aim to do that?
For most of biological samples, there exist many undesirable impurities inside them which we want to get rid of while recovering cells or particles of interest. For example, if we want to identify the source of infection that has rendered a patient in a severe condition, it is very difficult to do so because there are billions of blood cells in a milliliter of human blood while there are very few bacteria (~1-10 bugs/mL) or virus (~1-1000 copies/mL). Therefore, it is of utter importance that we selectively isolate these rare cells or particles of interest in biological samples to maximize the chance of detecting/analyzing them in further bioassays.
Spiral microfluidic sorter, which sorts particles or cells based on their sizes in a high-throughput, label-free manner can be an excellent candidate for doing this job. We aim to reduce undesirable background signals and to maximize target signals in biological assays (e.g. whole genome sequencing, fluorescent microscopy, etc.) by removing unwanted cells or particles in a sample while recovering almost all of target cells or particles. We are already applying our device to various kinds of biological samples such as blood, sputum, pus, saliva, stool, etc.
Figure 1 (A) Schematic of closed-loop separation (“C-sep”) spiral microfluidic device platform with negative selection scheme (B) Photograph of experimental setup (C) Magnified view of spiral microfluidic device (D) Comparison between input (100 times diluted whole blood) and microfluidics (MF)-treated samples
Vision for future
With the wide applicability of our spiral microfluidic sorter device and sample preparation experience, I envision that it will be possible to identify/detect very rare cells or particles from various biological samples through appropriate choice of bioassays, which at the moment might seem almost impossible.
1. Roby P. Bhattacharyya, Mark Walker, Rich Boykin, Sophie S. Son, Jamin Liu, Austin C. Hachey, Peijun Ma, Lidan Wu, Kyungyong Choi, Kaelyn C. Cummins, Maura Benson, Jennifer Skerry, Hyunryul Ryu, Sharon Y. Wong, Marcia B. Goldberg, Jongyoon Han, Virginia M. Pierce, Lisa A. Cosimi, Noam Shoresh, Jonathan Livny, Joseph Beechem, and Deborah T. Hung , “Rapid identification and phylogenetic classification of diverse bacterial pathogens in a multiplexed hybridization assay targeting ribosomal RNA,” Scientific Reports, Vol. 9, pp. 4516, 2019
2. Kyungyong Choi, Hyunryul Ryu, Katherine J. Siddle, Anne Piantadosi, Lisa Freimark, Daniel J. Park, Pardis Sabeti, and Jongyoon Han, “Negative Selection by Spiral Inertial Microfluidics Improves Viral Recovery and Sequencing from Blood”, Analytical Chemistry, Vol. 90, No. 7, pp. 4657-4662, 2018
3. Hyunryul Ryu, Kyungyong Choi, Yanyan Qu, Taehong Kwon, Janet S. Lee and Jongyoon Han, “Label-free Neutrophil Enrichment from Patient-derived Airway Secretion Using Closed-loop Inertial Microfluidics,” Journal of Visualized Experiments, Vol. 136, e57673, DOI:10.3791/57673, 2018
4. Hyunryul Ryu, Kyungyong Choi, Yanyan Qu, Taehong Kwon, Janet S. Lee, and Jongyoon Han “Patient-Derived Airway Secretion Dissociation Technique To Isolate and Concentrate Immune Cells Using Closed-Loop Inertial Microfluidics”, Analytical Chemistry, Vol. 89, No. 10, pp. 5549-5556, 2017
1. Kyungyong Choi, Wei Ouyang, Hyunryul Ryu, and Jongyoon Han, “CULTURE- AND PCR-FREE DETECTON OF LOW ABUNDANCE BACTERIA FROM BLOOD WITHIN AN HOUR”, The 22th International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS), Nov. 11-15, 2018, Kaohsiung, TAIWAN
2. Kyungyong Choi, Hyunryul Ryu, Lidan Wu, and Jongyoon Han, “NEGATIVE ISOLATION OF BACTERIA FROM THE WHOLE BLOOD USING CLOSED-LOOP INERTIAL AND MAGNETIC-ACTIVATED CELL SORTING”, The 20th International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS), Oct. 9-13, 2016, Dublin, IRELAND
3. Hyunryul Ryu, Kyungyong Choi, Yanyan Qu, Taehong Kwon, Janet Lee, and Jongyoon Han, “RARE-CELL ENRICHMENT USING CLOSED-LOOP OPERATION OF SPIRAL MICROFLUIDICS”, The 20th International Conference on Miniaturized Systems for Chemistry and Life Sciences, µTAS 2016 Conference, Oct. 9-13, 2016, Dublin, IRELAND