8
L. Hao and H. Gu
It is noteworthy that Prof. Yiyang Dong’s lab developed a non-labeled UVMag
SELEX as a complementary selection strategy to FluMag-SELEX for successful
selection of class-specific aptamers, the readers are suggested herein to browse
Chap. 13 in this book for more details.
1.3.2.3 On-Chip Selection
Chip-based microfluidic SELEX (M-SELEX) integrating magnetic bead-assisted
SELEX with microfluidics technology has been documented lately [24, 25]. Such
chips have greatly improved the efficiency of SELEX, possibly due to their precise
control of sample and reagent transport, mixing, and incubation temperatures, and MSELEX methods have been demonstrated to be effective for a wide variety of molecular targets that can be immobilized on bead surfaces, including small molecules,
proteins, and whole cells [19, 26]. The advantages of the chip-based M-SELEX are
listed as follows. First, microfluidic systems are more compact and consume less
sample. Second, the devices can be developed with higher automation thus the selection rounds can be reduced and the selection time can be also saved. Third, multiple
targets can be selected using an integrated microfluidic platform.
Three major cardiovascular biomarkers, NT-proBNP, hcTnI, and fibrinogen were
selected using an integrated microfluidic platform [27]. Automation of the screening
process on the microfluidic SELEX system resulted in a continuous SELEX cycles,
without any offline procedures, including on-chip PCR amplification with highly
efficient microdevices and temperature control modules. As a result, candidates with
high affinity and specificity could be screened for a specific target within five rounds
of selection in only 8 h, thereby reducing the time and efforts in comparison to
conventional SELEX. The selection principle of these chip-based selection devices
is illustrated in Fig. 1.5.
1.3.3 Simplifying Operations
1.3.3.1 Capture SELEX
Capture SELEX is a new kind of immobilization-based SELEX. This SELEX technology immobilizes the single-strand oligonucleotide library instead of the target
molecule to the supporting matrix, such as magnetic beads and agarose beads, using
noncovalent equilibrium. The fixation of the library is much easier to operate than
that of target molecule. According to the principle of base pairing, a short sequence
(bridge sequence) is designed to complement the partial sequence of the fixed region
of the oligonucleotide library. Thus, the library is fixed noncovalently by bridge
sequence. When a target exists, the affinity aptamers suspended on the fixed matrix
fold into specific three-dimensional structures and dissociate to bind to the target
specifically, while the sequences that cannot recognize the target molecule still
L. Hao and H. Gu
It is noteworthy that Prof. Yiyang Dong’s lab developed a non-labeled UVMag
SELEX as a complementary selection strategy to FluMag-SELEX for successful
selection of class-specific aptamers, the readers are suggested herein to browse
Chap. 13 in this book for more details.
1.3.2.3 On-Chip Selection
Chip-based microfluidic SELEX (M-SELEX) integrating magnetic bead-assisted
SELEX with microfluidics technology has been documented lately [24, 25]. Such
chips have greatly improved the efficiency of SELEX, possibly due to their precise
control of sample and reagent transport, mixing, and incubation temperatures, and MSELEX methods have been demonstrated to be effective for a wide variety of molecular targets that can be immobilized on bead surfaces, including small molecules,
proteins, and whole cells [19, 26]. The advantages of the chip-based M-SELEX are
listed as follows. First, microfluidic systems are more compact and consume less
sample. Second, the devices can be developed with higher automation thus the selection rounds can be reduced and the selection time can be also saved. Third, multiple
targets can be selected using an integrated microfluidic platform.
Three major cardiovascular biomarkers, NT-proBNP, hcTnI, and fibrinogen were
selected using an integrated microfluidic platform [27]. Automation of the screening
process on the microfluidic SELEX system resulted in a continuous SELEX cycles,
without any offline procedures, including on-chip PCR amplification with highly
efficient microdevices and temperature control modules. As a result, candidates with
high affinity and specificity could be screened for a specific target within five rounds
of selection in only 8 h, thereby reducing the time and efforts in comparison to
conventional SELEX. The selection principle of these chip-based selection devices
is illustrated in Fig. 1.5.
1.3.3 Simplifying Operations
1.3.3.1 Capture SELEX
Capture SELEX is a new kind of immobilization-based SELEX. This SELEX technology immobilizes the single-strand oligonucleotide library instead of the target
molecule to the supporting matrix, such as magnetic beads and agarose beads, using
noncovalent equilibrium. The fixation of the library is much easier to operate than
that of target molecule. According to the principle of base pairing, a short sequence
(bridge sequence) is designed to complement the partial sequence of the fixed region
of the oligonucleotide library. Thus, the library is fixed noncovalently by bridge
sequence. When a target exists, the affinity aptamers suspended on the fixed matrix
fold into specific three-dimensional structures and dissociate to bind to the target
specifically, while the sequences that cannot recognize the target molecule still