Design and development of ferrocene-containing chitosan-cografted-branched polyethylenimine redox conjugates for monitoring free flap failure after reconstructive surgery.

We reported a proof-of-concept study of developing an electrochemical biosensor for prolonged continuous monitoring free flap failure caused by vascular occlusion after reconstructive surgery. Ferrocene (Fc)-containing Chitosan-cografted-Branched Polyethylenimine redox conjugates (CHIT-Fc-co-BPEI-Fc) were used as pH-tuneable matrix to attach the target enzymes (glucose oxidase ≡ GOD and lactate oxidase ≡ LOD, respectively) to build up the corresponding GOD-sensor and LOD-sensor. The sensitivity of GOD-/LOD-sensor was found to be 2.

Paper-Based MicroRNA Expression Profiling from Plasma and Circulating Tumor Cells.

Background: Molecular characterization of circulating tumor cells (CTCs) holds great promise for monitoring metastatic progression and characterizing metastatic disease. However, leukocyte and red blood cell contamination of routinely isolated CTCs makes CTC-specific molecular characterization extremely challenging.

Methods: Here we report the use of a paper-based medium for efficient extraction of microRNAs (miRNAs) from limited amounts of biological samples such as rare CTCs harvested from cancer patient blood.

Highly sensitive KRAS mutation detection from formalin-fixed paraffin-embedded biopsies and circulating tumour cells using wild-type blocking polymerase chain reaction and Sanger sequencing.

Background And Objectives: Among patients with colorectal cancer (CRC), KRAS mutations were reported to occur in 30-51 % of all cases. CRC patients with KRAS mutations were reported to be non-responsive to anti-epidermal growth factor receptor (EGFR) monoclonal antibody (MoAb) treatment in many clinical trials. Hence, accurate detection of KRAS mutations would be critical in guiding the use of anti-EGFR MoAb therapies in CRC.

Microsieve lab-chip device for rapid enumeration and fluorescence in situ hybridization of circulating tumor cells.

Herein we present a lab-chip device for highly efficient and rapid detection of circulating tumor cells (CTCs) from whole blood samples. The device utilizes a microfabricated silicon microsieve with a densely packed pore array (10(5) pores per device) to rapidly separate tumor cells from whole blood, utilizing the size and deformability differences between the CTCs and normal blood cells. The whole process, including tumor cell capture, antibody staining, removal of unwanted contaminants and immunofluorescence imaging, was performed directly on the microsieve within an integrated microfluidic unit, interconnected to a peristaltic pump for fluid regulation and a fluorescence microscope for cell counting.

A simple, high sensitivity mutation screening using Ampligase mediated T7 endonuclease I and Surveyor nuclease with microfluidic capillary electrophoresis.

Mutation and polymorphism detection is of increasing importance for a variety of medical applications, including identification of cancer biomarkers and genotyping for inherited genetic disorders. Among various mutation-screening technologies, enzyme mismatch cleavage (EMC) represents a great potential as an ideal scanning method for its simplicity and high efficiency, where the heteroduplex DNAs are recognized and cleaved into DNA fragments by mismatch-recognizing nucleases. Thereby, the enzymatic cleavage activities of the resolving nucleases play a critical role for the EMC sensitivity.

De novo gene synthesis design using TmPrime software.

This chapter presents TmPrime, a computer program to design oligonucleotide for both ligase chain reaction (LCR)- and polymerase chain reaction (PCR)-based de novo gene synthesis. The program divides a long input DNA sequence based on user-specified melting temperatures and assembly conditions, and dynamically optimizes the length of oligonucleotides to achieve homologous melting temperatures. The output reports the melting temperatures, oligonucleotide sequences, and potential formation of secondary structures in a PDF file, which will be sent to the user via e-mail.

TopDown real-time gene synthesis.

This chapter introduces a simple, cost-effective TopDown one-step gene synthesis method, which is suitable for the sequence assembly of fairly long DNA. This method can be distinguished from conventional gene synthesis methods by two key features: (1) the melting temperature of the outer primers is designed to be ∼8°C lower than that of the assembly oligonucleotides, and (2) different annealing temperatures are utilized to selectively control the efficiencies of oligonucleotide assembly and full-length template amplification. This method eliminates the interference between polymerase chain reactions (PCR) assembly and amplification in one-step gene synthesis.

New insights into the de novo gene synthesis using the automatic kinetics switch approach.

Here we present a simple, highly efficient, universal automatic kinetics switch (AKS) gene synthesis method that enables synthesis of DNA up to 1.6kbp from 1nM oligonucleotide with just one polymerase chain reaction (PCR) process. This method eliminates the interference between the PCR assembly and amplification in one-step gene synthesis and simultaneously maximizes the amplification of emerged desired DNA by using a pair of flanked primers.

Hybrid sample-inverted reflow and soft-lithography technique for fabrication of conicoid microlens arrays.

We report a cost-effective fabrication method, with a combination of the sample-inverted reflow technique and the soft-lithography replication method, to fabricate conicoid refractive microlens arrays (MLAs), including hyperboloid, paraboloid, and ellipsoid MLAs in inorganic-organic hybrid SiO2-ZrO2 solgel material. The fabrication procedures involve two basic steps. First, a master of the conicoid MLA was made in photoresist by the sample-inverted reflow technique.

Reflowed solgel spherical microlens for high-efficiency optical coupling between a laser diode and a single-mode fiber.

To improve the coupling efficiency between a laser diode and a single-mode fiber, we propose a two-microlens coupling scheme that uses two solgel spherical microlenses for high coupling efficiency. The conventional reflow technique was employed and extended to the inorganic-organic hybrid SiO2/ZrO2 solgel material to form the microlenses. Preliminary results show that the coupling efficiency was increased to--1.

Fabrication of concave refractive microlens arrays in solgel glass by a simple proximity-effect-assisted reflow technique.

We report a simple method for fabricating a concave refractive microlens array (MLA) in solgel glass by using a proximity-effect-assisted reflow technique. The solgel concave refractive MLA that we fabricated had excellent surface smoothness; good dimensional conformity, with an 8.23% nonuniformity of the microlens elements; and structural perfection, with a biggest deviation of 1% from a perfect concave spherical crown.

Reflow technique for the fabrication of an elliptical microlens array in sol-gel material.

A simple reflow technique is employed for the fabrication of elliptical refractive microlens arrays (MLAs) on a low-cost inorganic-organic SiO2/ZrO2 sol-gel glass. The measured results show that the fabricated elliptical microlenses in a 256 x 512 array have excellent surface and dimensional qualities in terms of smoothness and uniformity. It is also shown that the optical parameters of the MLAs, such as the focal length and aperture dimension, can be accurately controlled.