Instrument-Free Protein Microarray Fabrication for Accurate Affinity Measurements

2020 ◽  
Author(s):  
Iris Celebi ◽  
Matthew T. Geib ◽  
Elisa Chiodi ◽  
Nese Lortlar Ünlü ◽  
Fulya Ekiz Kanik ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Low Cost ◽  
Protein Microarray ◽  
Active Surface ◽  
Protein Microarrays ◽  
Free Protein ◽  
Microarray Fabrication ◽  
Antigen Antibody ◽  
Imaging Sensor ◽  
Protein Assays

Protein microarrays have gained popularity as an attractive tool for various fields, including drug and biomarker development, and diagnostics. Thus, multiplexed binding affinity measurements in microarray format has become crucial. The preparation of microarray-based protein assays relies on precise dispensing of probe solutions to achieve efficient immobilization onto an active surface. The prohibitively high cost of equipment and the need for trained personnel to operate high complexity robotic spotters for microarray fabrication are significant detriments for researchers, especially for small laboratories with limited resources. Here, we present a low-cost, instrument-free dispensing technique by which users who are familiar with micropipetting can manually create multiplexed protein assays that show improved capture efficiency and noise level in comparison to that of the robotically spotted assays. In this study, we compare the efficiency of manually and robotically dispensed α-Lactalbumin probe spots by analyzing the binding kinetics obtained from the interaction with anti-α-Lactalbumin antibodies, using the interferometric reflectance imaging sensor platform. We show that the protein arrays prepared by micropipette manual spotting meet and exceed the performance of those prepared by state-of-the-art robotic spotters. These instrument-free protein assays have higher binding signal (~4-fold improvement) and a ~3-fold better signal-to-noise ratio (SNR) in binding curves, when compared to the data acquired by averaging of 75 robotic spots corresponding to the same effective sensor surface area. We demonstrate the potential of determining antigen-antibody binding coefficients in 24-multiplexed chip format with less than 5% measurement error.

scholarly journals Instrument-Free Protein Microarray Fabrication for Accurate Affinity Measurements

Biosensors ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 158
Author(s):  
Iris Celebi ◽  
Matthew T. Geib ◽  
Elisa Chiodi ◽  
Nese Lortlar Ünlü ◽  
Fulya Ekiz Kanik ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Low Cost ◽  
Protein Microarray ◽  
Active Surface ◽  
Protein Microarrays ◽  
Free Protein ◽  
Microarray Fabrication ◽  
Antigen Antibody ◽  
Imaging Sensor ◽  
Protein Assays

Protein microarrays have gained popularity as an attractive tool for various fields, including drug and biomarker development, and diagnostics. Thus, multiplexed binding affinity measurements in microarray format has become crucial. The preparation of microarray-based protein assays relies on precise dispensing of probe solutions to achieve efficient immobilization onto an active surface. The prohibitively high cost of equipment and the need for trained personnel to operate high complexity robotic spotters for microarray fabrication are significant detriments for researchers, especially for small laboratories with limited resources. Here, we present a low-cost, instrument-free dispensing technique by which users who are familiar with micropipetting can manually create multiplexed protein assays that show improved capture efficiency and noise level in comparison to that of the robotically spotted assays. In this study, we compare the efficiency of manually and robotically dispensed α-lactalbumin probe spots by analyzing the binding kinetics obtained from the interaction with anti-α-lactalbumin antibodies, using the interferometric reflectance imaging sensor platform. We show that the protein arrays prepared by micropipette manual spotting meet and exceed the performance of those prepared by state-of-the-art robotic spotters. These instrument-free protein assays have a higher binding signal (~4-fold improvement) and a ~3-fold better signal-to-noise ratio (SNR) in binding curves, when compared to the data acquired by averaging 75 robotic spots corresponding to the same effective sensor surface area. We demonstrate the potential of determining antigen-antibody binding coefficients in a 24-multiplexed chip format with less than 5% measurement error.

Instrument-Free Protein Microarray Fabrication for Accurate Affinity Measurements

2020 ◽  
Author(s):  
Iris Celebi ◽  
Matthew T. Geib ◽  
Elisa Chiodi ◽  
Nese Lortlar Ünlü ◽  
Fulya Ekiz Kanik ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Low Cost ◽  
Protein Microarray ◽  
Active Surface ◽  
Protein Microarrays ◽  
Free Protein ◽  
Microarray Fabrication ◽  
Antigen Antibody ◽  
Imaging Sensor ◽  
Protein Assays

Protein microarrays have gained popularity as an attractive tool for various fields, including drug and biomarker development, and diagnostics. Thus, multiplexed binding affinity measurements in microarray format has become crucial. The preparation of microarray-based protein assays relies on precise dispensing of probe solutions to achieve efficient immobilization onto an active surface. The prohibitively high cost of equipment and the need for trained personnel to operate high complexity robotic spotters for microarray fabrication are significant detriments for researchers, especially for small laboratories with limited resources. Here, we present a low-cost, instrument-free dispensing technique by which users who are familiar with micropipetting can manually create multiplexed protein assays that show improved capture efficiency and noise level in comparison to that of the robotically spotted assays. In this study, we compare the efficiency of manually and robotically dispensed α-Lactalbumin probe spots by analyzing the binding kinetics obtained from the interaction with anti-α-Lactalbumin antibodies, using the interferometric reflectance imaging sensor platform. We show that the protein arrays prepared by micropipette manual spotting meet and exceed the performance of those prepared by state-of-the-art robotic spotters. These instrument-free protein assays have higher binding signal (~4-fold improvement) and a ~3-fold better signal-to-noise ratio (SNR) in binding curves, when compared to the data acquired by averaging of 75 robotic spots corresponding to the same effective sensor surface area. We demonstrate the potential of determining antigen-antibody binding coefficients in 24-multiplexed chip format with less than 5% measurement error.

A critical comparison of protein microarray fabrication technologies

The Analyst ◽  
2014 ◽  
Vol 139 (6) ◽  
pp. 1303-1326 ◽  
Author(s):  
Valentin Romanov ◽  
S. Nikki Davidoff ◽  
Adam R. Miles ◽  
David W. Grainger ◽  
Bruce K. Gale ◽  
...  
Keyword(s):  
High Throughput ◽  
Protein Microarray ◽  
Protein Microarrays ◽  
Antibody Affinity ◽  
High Throughput Analysis ◽  
Critical Comparison ◽  
Binding Partners ◽  
Fundamental Information ◽  
Microarray Fabrication ◽  
Analytical Tools

Of the diverse analytical tools used in proteomics, protein microarrays possess the greatest potential for providing fundamental information on protein, ligand, analyte, receptor, and antibody affinity-based interactions, binding partners and high-throughput analysis.

SURFACE CHEMISTRY FOR PROTEIN MICROARRAYS

2007 ◽  
Vol 06 (02) ◽  
pp. 109-116 ◽  
Author(s):  
ATHENA GUO ◽  
XIAOYANG ZHU
Keyword(s):  
Surface Chemistry ◽  
Protein Microarray ◽  
Three Dimensional ◽  
Protein Molecule ◽  
Protein Microarrays ◽  
Protein Chip ◽  
Dimensional Structure ◽  
Ideal Situation ◽  
Protein Molecules ◽  
Microarray Fabrication

Protein microarray or protein chip is an important tool in proteomics. However, duplicating the success of the DNA chip for the protein chip has been difficult. This account discusses a key issue in protein microarray development, i.e., surface chemistry. Ideally, the surface chemistry for protein microarray fabrication should satisfy the following criteria: the surface resists nonspecific adsorption; functional groups for the facile immobilization of protein molecules of interest are readily available; bonding between a protein molecule and a solid surface is balanced to provide sufficient stability but minimal disturbance on the delicate three-dimensional structure of the protein; linking chemistry allows the control of protein orientation; the local chemical environment favors the immobilized protein molecules to retain their native conformation; and finally, the specificity of linking chemistry is so high that no pre-purification of proteins is required. Strategies to achieve such an ideal situation are discussed, with successful examples from our laboratories illustrated. Finally, the need of surface technology for membrane protein microarray fabrication is addressed.

scholarly journals Efficient Estimation of CFO-Affected OFDM BER Floor in Small Cells with Resource-Limited IoT End-Points

Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3747
Author(s):  
Adriana Lipovac ◽  
Vlatko Lipovac ◽  
Borivoj Modlic
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Carrier Frequency Offset ◽  
Signal To Noise Ratio ◽  
Low Cost ◽  
Error Recovery ◽  
Efficient Estimation ◽  
Analytical Models ◽  
Small Cells ◽  
End Points ◽  
Power Delay Profile

Contemporary wireless networks dramatically enhance data rates and latency to become a key enabler of massive communication among various low-cost devices of limited computational power, standardized by the Long-Term Evolution (LTE) downscaled derivations LTE-M or narrowband Internet of Things (NB IoT), in particular. Specifically, assessment of the physical-layer transmission performance is important for higher-layer protocols determining the extent of the potential error recovery escalation upwards the protocol stack. Thereby, it is needed that the end-points of low processing capacity most efficiently estimate the residual bit error rate (BER) solely determined by the main orthogonal frequency-division multiplexing (OFDM) impairment–carrier frequency offset (CFO), specifically in small cells, where the signal-to-noise ratio is large enough, as well as the OFDM symbol cyclic prefix, preventing inter-symbol interference. However, in contrast to earlier analytical models with computationally demanding estimation of BER from the phase deviation caused by CFO, in this paper, after identifying the optimal sample instant in a power delay profile, we abstract the CFO by equivalent time dispersion (i.e., by additional spreading of the power delay profile that would produce the same BER degradation as the CFO). The proposed BER estimation is verified by means of the industry-standard LTE software simulator.

scholarly journals Tomographic Proximity Imaging Using Conductive Sheet for Object Tracking

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2736
Author(s):  
Zehao Li ◽  
Shunsuke Yoshimoto ◽  
Akio Yamamoto
Keyword(s):  
Inverse Problem ◽  
Theoretical Model ◽  
Low Cost ◽  
Hand Tracking ◽  
Depth Camera ◽  
Capacitance Density ◽  
Evaluation Test ◽  
Density Problem ◽  
Imaging Sensor ◽  
Tomographic Approach

This paper proposes a proximity imaging sensor based on a tomographic approach with a low-cost conductive sheet. Particularly, by defining capacitance density, physical proximity information is transformed into electric potential. A novel theoretical model is developed to solve the capacitance density problem using the tomographic approach. Additionally, a prototype is built and tested based on the model, and the system solves an inverse problem for imaging the capacitance density change that indicates the object’s proximity change. In the evaluation test, the prototype reaches an error rate of 10.0–15.8% in horizontal localization at different heights. Finally, a hand-tracking demonstration is carried out, where a position difference of 33.8–46.7 mm between the proposed sensor and depth camera is achieved at 30 fps.

scholarly journals All-Optical Non-Inverted Parity Generator and Checker Based on Semiconductor Optical Amplifiers

2021 ◽  
Vol 11 (4) ◽  
pp. 1499
Author(s):  
Bingchen Han ◽  
Junyu Xu ◽  
Pengfei Chen ◽  
Rongrong Guo ◽  
Yuanqi Gu ◽  
...  
Keyword(s):  
Optical Amplifiers ◽  
Signal To Noise Ratio ◽  
Low Cost ◽  
Extinction Ratio ◽  
Semiconductor Optical Amplifiers ◽  
Optical Signal ◽  
Probe Light ◽  
All Optical ◽  
Negative Effect ◽  
Parity Generator

An all-optical non-inverted parity generator and checker based on semiconductor optical amplifiers (SOAs) are proposed with four-wave mixing (FWM) and cross-gain modulation (XGM) non-linear effects. A 2-bit parity generator and checker using by exclusive NOR (XNOR) and exclusive OR (XOR) gates are implemented by first SOA and second SOA with 10 Gb/s return-to-zero (RZ) code, respectively. The parity and check bits are provided by adjusting the center wavelength of the tunable optical bandpass filter (TOBPF). A saturable absorber (SA) is used to reduce the negative effect of small signal clock (Clk) probe light to improve extinction ratio (ER) and optical signal-to-noise ratio (OSNR). For Pe and Ce (even parity bit and even check bit) without Clk probe light, ER and OSNR still maintain good performance because of the amplified effect of SOA. For Po (odd parity bit), ER and OSNR are improved to 1 dB difference for the original value. For Co (odd check bit), ER is deteriorated by 4 dB without SA, while OSNR is deteriorated by 12 dB. ER and OSNR are improved by about 2 dB for the original value with the SA. This design has the advantages of simple structure and great integration capability and low cost.

scholarly journals Polyvinylsulfonic acid: A Low-cost RNase inhibitor for enhanced RNA preservation and cell-free protein translation

Bioengineered ◽  
2017 ◽  
Vol 9 (1) ◽  
pp. 90-97 ◽  
Author(s):  
Conner C. Earl ◽  
Mark T. Smith ◽  
Richard A. Lease ◽  
Bradley C. Bundy
Keyword(s):  
Low Cost ◽  
Protein Translation ◽  
Rnase Inhibitor ◽  
Free Protein ◽  
Polyvinylsulfonic Acid ◽  
Rna Preservation

Event-Locked Time-Resolved Fourier Spectroscopy

1997 ◽  
Vol 51 (8) ◽  
pp. 1106-1112 ◽  
Author(s):  
H. Weidner ◽  
R. E. Peale
Keyword(s):  
Signal To Noise Ratio ◽  
Low Cost ◽  
Michelson Interferometer ◽  
Far Infrared ◽  
Time Base ◽  
The Novel ◽  
Time Resolved ◽  
Mathematical Algorithm ◽  
Scan Time ◽  
Recorded Data

A low-cost method of adding time-resolving capability to commercial Fourier transform spectrometers with a continuously scanning Michelson interferometer has been developed. This method is specifically designed to eliminate noise and artifacts caused by mirror-speed variations in the interferometer. The method exists of two parts: (1) a novel timing scheme for synchronizing the transient events under study and the digitizing of the interferogram and (2) a mathematical algorithm for extracting the spectral information from the recorded data. The novel timing scheme is a modification of the well-known interleaved, or stroboscopic, method. It achieves the same timing accuracy, signal-to-noise ratio, and freedom from artifacts as step-scan time-resolving Fourier spectrometers by locking the sampling of the interferogram to a stable time base rather than to the occurrences of the HeNe fringes. The necessary pathlength-difference information at which samples are taken is obtained from a record of the mirror speed. The resulting interferograms with uneven pathlength-difference spacings are transformed into wavenumber space by least-squares fits of periodic functions. Spectra from the far-infrared to the upper visible at resolutions up to 0.2 cm−1 are used to demonstrate the utility of this method.

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