No abstract

Micropost‐based microfluidic devices are widely used for microvascular network (MVN) formation in diverse research fields. However, consistently generating perfusable MVNs of physiological morphology and dimension has proven to be challenging. Here, how initial seeding parameters determine key characteristics of MVN formation is investigated and a robust two‐step seeding strategy to generate perfusable physiological MVNs in microfluidic devices is established.

Fluorescence in situ hybridization (FISH) is one of the recommended techniques for human epidermal growth factor receptor 2 (HER2) status assessment on cancer tissues. Here we develop microfluidics-assisted FISH (MA-FISH), in which hybridization of the FISH probes with their target DNA strands is obtained by applying square-wave oscillatory flows of diluted probe solutions in a thin microfluidic chamber of 5 μl volume. By optimizing the experimental parameters, MA-FISH decreases the consumption of the expensive probe solution by a factor 5 with respect to the standard technique, and reduces the hybridization time to 4 h, which is four times faster than in the standard protocol. To validate the method, we blindly conducted HER2 MA-FISH on 51 formalin-fixed paraffin-embedded tissue slides of 17 breast cancer samples, and compared the results with standard HER2 FISH testing. HER2 status classification was determined according to published guidelines, based on average number of HER2 copies per cell and average HER2/CEP17 ratio. Excellent agreement was observed between the two methods, supporting the validity of MA-FISH and further promoting its short hybridization time and reduced reagent consumption.

No abstract

This paper reports design, fabrication and characterization of an air-actuated microvalve and a micropump made of thermoplastic materials. The bonding process was carried out by thermal fusion process with no particular surface treatment. The developed microvalve was used as a reversible switch for controlling both liquid flow and electrical field. Bonding strength of the fabricated microvalves could withstand of liquid and air pressures of up to 600 kPa with no burst failure. The micropump made of three connected microvalves, actuated by compressed air, could generate a liquid flow rate of up to 85 µl/min. The proposed microvalve and micropump can be used as prefabricated off-the-shelf microfluidic functional elements for easy and rapid integration with thermoplastic microfluidic circuitries in a plug-and-play arrangement.