Browsing by Subject "Lab-on-a-chip"

Now showing 1 - 4 of 4

Open Access
Çip-Üstü-Laboratuvar (ÇÜL) teknolojisinin gıda mikrobiyolojisindeki uygulamaları
(Sidas Medya Limited Şirketi, 2018) Düven, G.; Çetin, Barbaros; Kışla, D.
Son 20 yılda ortaya çıkan mikro-kanal yapılarında mikro-litreler mertebesinde akışkanın proses edilmesi için kullanılan çip-üstü-laboratuvar (ÇÜL) sistemleri konvansiyonel yöntemlere bir alternatif oluşturmaktadır. Mikro-yapıların kendine has özelliklerinden dolayı ÇÜL sistemleri, karmaşık analizleri geleneksel yöntemlerle karşılaştırıldığında daha düşük maliyette, daha düşük enerji, daha düşük kimyasal sarfiyatı ile daha verimli bir şekilde yapabilmekte ve bu yönleriyle birçok alanda (biyomedikal, gıda, kimya, tıp, eczacılık, tarım vb.) çok değerli bir seçenek oluşturmaktadır. Ayrıca bu sistemler otomasyona uygundur ve taşınabilir olma potansiyelleri vardır. Özellikle gıda endüstrisinde bazı durumlarda analiz sonuçlarının hızlı alınabilmesi işletme için büyük önem taşımaktadır. Çip-üstü laboratuvar teknolojisi bu nedenle gıda endüstrisinde özellikle mikrobiyolojik analizlerde hızlı sonuç vermesi, uzman personel gerektirmemesi, az örneğe ihtiyaç duyması vb. özellikleri ile son zamanlarda oldukça önem taşımaktadır. Bu çalışmada, ÇÜL cihazlarının çalışma prensipleri, polimeraz zincir reaksiyonu (PZR), akış sitometrisi ve biyosensörler ile birlikte kullanıldığı entegre sistemler ve bu sistemlerin gıda mikrobiyolojisindeki uygulamaları anlatılmıştır.
Open Access
Dielectrophoresis in microfluidics technology
(2011) Çetin B.; Li, D.
Dielectrophoresis (DEP) is the movement of a particle in a non-uniform electric field due to the interaction of the particle's dipole and spatial gradient of the electric field. DEP is a subtle solution to manipulate particles and cells at microscale due to its favorable scaling for the reduced size of the system. DEP has been utilized for many applications in microfluidic systems. In this review, a detailed analysis of the modeling of DEP-based manipulation of the particles is provided, and the recent applications regarding the particle manipulation in microfluidic systems (mainly the published works between 2007 and 2010) are presented. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Open Access
An optofluidic point-of-care device for quantitative investigation of erythrocyte aggregation during coagulation
(Elsevier B.V., 2018) Işıksaçan, Ziya; Hastar, Nurcan; Erel, Ö.; Elbüken, Çağlar
Coagulation, the process leading to clot formation with the interplay of blood constituents, is a self-regulating mechanism, requiring attentive and periodic monitoring for numerous clinical cases. Erythrocyte aggregation (EA) is a characteristic behaviour of erythrocytes forming reversible clumps especially in vitro at low shear rates. The effect of EA during coagulation is overlooked in whole blood (WB) clotting assays, and the relationship between the two mechanisms is not well understood. We present an optofluidic point-of-care device enabling quantitative investigation of EA from 50 μl WB during the coagulation process. Not only did we explain the coagulation mechanism considering EA, but we also demonstrated coagulation time measurement from optical EA analysis. The device consists of a disposable cartridge and a handheld analyzer containing a pinch valve for fluid motion and optics for transmitted light measurement. Following the sample introduction and cessation of the valve operation, the optical signal is the lowest due to shear-induced cell disaggregation. Then, the signal increases due to EA until reaching a peak, indicating blood clotting. The working principle was proven through clinical tests for prothrombin time measurement. In addition to revealing the relation between coagulation and aggregation, this device is promising for rapid WB coagulation time measurement.
Open Access
The Yin and Yang of exosome isolation methods: conventional practice, microfluidics, and commercial kits
(Elsevier Inc, 2022-01) Shirejini, Saeedreza Zeibi; İnci, Fatih
Exosomes are a subset of extracellular vesicles released from various cells, and they can be found in different bodily fluids. Exosomes have been utilized as biomarkers to diagnose many diseases and to monitor therapy efficiency as they represent the status and origin of the cell, which they are released from. Considering that they co-exist in bodily fluids with other types of particles, their isolation still remains challenging since conventional methods are time-consuming, user-dependent, and result in low isolation yield. This review summarizes the conventional strategies and microfluidic-based methods for exosome isolation along with their strengths and limitations. In particular, microfluidic devices emerge as a promising approach to tackle the existing limitations of conventional methods, and they provide unique features, such as operating with minute volume of samples and rapid process, in order to isolate exosomes with the high yield and the high purity, which make them unprecedented tools for molecular biology and clinical applications in exosome research. This review further elaborates on the existing microfluidic-based exosome isolation methods and denotes their benefits and drawbacks. Herein, we also introduce various commercially available platforms and kits for exosome isolation along with their working principles.