Conventional Amplification Research Articles

Fully Automated Lab-On-A-Disc Platform for Loop-Mediated Isothermal Amplification Using Micro-Carbon-Activated Cell Lysis.

Fast and fully automated deoxyribonucleic acid (DNA) amplification methods are of interest in the research on lab-on-a-disc (LOD) platforms because of their full compatibility with the spin-column mechanism using centrifugal force. However, the standard procedures followed in DNA amplification require accurate noncontact temperature control as well as cell lysis at a low temperature to prevent damage to the LOD platform. This requirement makes it challenging to achieve full automation of DNA amplification on an LOD. In this paper, a fully automated LOD capable of performing cell lysis and amplification on a single compact disc of DNA samples is proposed. The proposed system uses micro-carbon to heat DNA samples without damaging the LOD as well as a noncontact heating system and an infrared camera sensor to remotely measure the real temperature of the amplification chamber. Compared with conventional DNA amplification systems, the proposed system has the advantage of full automation of the LOD platform. Experimental results demonstrated that the proposed system offers a stable heating method for DNA amplification and cell lysis.

Evaluation the intestinal level of LCN2/NGAL in patients with Clostridium difficile infection in the south of Iran

Clostridium difficile is a Gram-positive obligate anaerobic bacterium that recognized an important pathogen of humans. The present study aimed to evaluate the intestinal level of neutrophil gelatinase-associated lipocalin (NGAL) in patients with C. difficile infection (CDI) as a disease activity marker in the south of Iran. This cross-sectional study conducted from October 2017 to June 2018 on patients referred to Nemazee and Amir Hospital in Shiraz, South of Iran. Patients less than two years old were excluded from the study. The study population was consist of 46 cases (Symptomatic patients that confirmed as a CDI), and 21 control individuals (Asymptomatic patients colonized by C. difficile ). C. difficile isolates were identified by conventional microbiological producers and amplification of housekeeping gene by PCR method. The level of NGAL was determined by enzyme-linked immunosorbent assay (ELISA) according to the instructions of the kit manufacturer. The results showed that the level of NGAL in symptomatic patients' (case group) was higher than asymptomatic carriers (control group), 5.9 ng/mL vs. 4.1 ng/mL; however the observed difference was not statistically significant. Also, in both groups, the mean level of NGAL was significantly higher in patients with gastrointestinal diseases than others. In summary, despite all the limitations, the results of the present study indicate that the intestinal level of NGAL is a biological indicator of intestinal inflammation, regardless of CDI. However, further study needs to elucidate the role of NGAL in inflammation caused by bacterial infections.

Gain optimization of 100 × 40 Gbps high capacity DWDM fiber optical link using hybrid amplification techniques

This paper demonstrates the performance analysis of a 40-Gbps 100-channel dense wavelength division multiplexing link using a hybrid optical amplifier. The proposed optimized design of the hybrid optical amplifier which combines semiconductor optical amplifier (SoA), eErbium-doped fiber amplifier (EDFA) and Raman amplifier delivered significant flat gain across the operational spectrum, as well as for varying link lengths. During the analysis, it has been observed that the use of the hybrid optical amplifier allows the communication link length to be extended up to 100 km which otherwise is restricted in the range of 50–60 km with conventional amplification modes. For a 100-km-long fiber link, the hybrid amplification-assisted link delivered a decent gain of 16.23 dB with a bit error rate of 10−10. However, for the similar simulation parameters, SoA/EDFA-assisted link experience pronounced link performance deterioration as the link range is increased. Our proposed link was designed and analyzed using OptiSystem 14.2.

Conventional versus notch filter amplification for the treatment of tinnitus in adults with mild-to-moderate hearing loss.

Conventional hearing aids are commonly recommended for the treatment of tinnitus, though results of studies investigating the efficacy of hearing aid-based tinnitus treatments have been mixed. Recently, it has been suggested that the addition of a notch filter around the tinnitus frequency might enhance lateral inhibitory mechanisms and thereby improve tinnitus severity relative to traditional processing. The primary aim of this study was to compare the effects of conventional versus notch filter amplification strategies on subjective tinnitus severity in adults with mild-to-moderate hearing loss and no previous hearing aid experience. Thirty-nine adults (mean age=53.6 years; SD=9.7 years) with bilateral, mild to moderate sensorineural hearing loss and an established clinical history of stable, tonal tinnitus participated in this double-blinded study. Each participant was randomly assigned to complete a 12-week hearing aid trial using either a conventional amplification strategy or a strategy which applied a notch filter at the given participant's tinnitus pitch match frequency. Tinnitus-related handicap and distress were assessed before and after the hearing aid trial via the Tinnitus Handicap Inventory (Newman et al., 1996) and the Tinnitus Questionnaire (Hallam et al., 1988). Average tinnitus severity did not differ significantly between the conventional and notch filter amplification groups following treatment. Moreover, average pre- to post-intervention change scores were relatively low for both groups, indicating minimal effect of either treatment on tinnitus symptoms. Participant age, high-frequency pure-tone average hearing threshold, average daily hearing aid usage, and pre-intervention tinnitus severity ratings were not predictive of treatment success or failure. Results of the present study suggest no significant effect of either conventional or notch filter amplification on average ratings of tinnitus severity following a 12-week hearing aid trial. However, as clinically meaningful changes in tinnitus severity were identified for some participants, future work is needed to better identify those individuals most likely to benefit, as well as optimal amplification characteristics.

Quantitative LAMP and PCR Detection of Salmonella in Chicken Samples Collected from Local Markets around Pathum Thani Province, Thailand.

Salmonella is a bacterium that infects people when they consume contaminated food or liquids. To prevent humans from becoming ill, it is useful to have an efficient method of detecting Salmonella before the disease is passed on through the food chain. In this research, the efficiency of Salmonella detection was compared using the following four methods: conventional loop-mediated isothermal amplification (LAMP), PCR, quantitative LAMP (qLAMP), and qPCR. The artificial infection of chicken samples started with incubating of 10 mL of 108 CFU of S. typhimurium for 6 hr. and enriching for 2 hr. to represent real contamination of the samples. The results show that the sensitivity of Salmonella DNA detection in PCR, qPCR, LAMP, and qLAMP were 50 ng, 5 ng, 50 pg, and and 500 fg, respectively. Thirty samples of 10 g chicken were collected from 10 markets in Pathum Thani, Thailand; then, the infection was detected. The conventional LAMP, qLAMP, and qPCR methods detected Salmonella in all the chicken samples. However, the conventional PCR method detected Salmonella infection in only eight of the samples. Overall, the qLAMP method had the highest sensitivity of Salmonella DNA detection.

Molecular Identification of Some Respiratory Pathogens from Broiler Chickens in Sharkia Governorate, Egypt

In this study, we investigated the prevelance of avian influenza virus (AIV) (subtypes H5 and H9), infectious bronchitis virus (IBV), Newcastle disease virus (ND) and Mycoplasma gallisepticum (MG) incriminated in respiratory troubles among chicken broilers at different localities in Sharkia Governorate during 2013-2017 outbreaks. Out of 53 broiler flocks, 225 chickens showing respiratory manifestations were examined. Viral isolation from respiratory tissues, serological and molecular identification were done. Based on hemagglutination inhibition (HI) test, for 42 positive haemagglutinating allantoic fluids, the prevalence of NDV and AIV (H9 and H5 subtypes) was 64.3%, 45.3%and 2,4% respectively. Two diagnostic polymerase chain reaction (PCR) assays were used. Based on TaqMan probe base real-time PCR, 17/19, 10/42 and 1/42 flocks were confirmed to be infected with IBV, AIV subtype H9 and H5 respectively. Moreover, conventional PCR amplification for detection of Mycoplasma gallisepticum in 25 flocks was performed and revealed 56% (14/25) positive flocks. Subsequently, amplified products of three M. gallisepticum representative isolates were sequenced and phylogenitically analyzed with other strains on GenBank. The results revealed that the three examined isolates were wild type (field isolates).We could conclude that there were continuous circulation of different respiratory agents (viral (NDV, AIVH9 & H5, and IBV) and bacterial (MG) in broiler flocks in Sharkia Governorate either as single or mixed infection although wide using of different vaccination regimes and antibiotics so early diagnosis of these pathogens is considered the most effective tool in prevention and control of diseases.

Therapeutic challenges and clinical characteristics of single-sided deafness in children

IntroductionThe clinical implications of single-sided deafness (SSD) in children has historically been underappreciated by patients and providers alike, despite a large body of literature on the wide-ranging neurocognitive, language, scholastic, and functional impairments that occur. Conventional amplification options are marked by variable results and frequent loss of follow-up. MethodsRetrospective case series for pediatric SSD from 2008 to 2018. Results88 children with congenital SSD were identified. Seventeen (N = 17/88, 23.9%) passed their newborn hearing screen. Median age at first otolaryngology evaluation was 0.65 years (range 0.1–16.9 years). Most common etiologies included cochlear nerve deficiency (N = 39, CND, 44.3%), unknown (N = 30, 35.2%), inner ear malformation (N = 7, 8.0%), and congenital cytomegalovirus (N = 6, 6.8%). 32.5% of patients elected for continued observation only, followed by bone conduction hearing aid (27.7%), contralateral routing of sound aid (20.5%), conventional hearing aid (13.3%), or cochlear implant (6%). Lack of follow-up at ≥1 year was common (39.8%). Of those with device use data (N = 39), 84.7% reported either discontinued or <6 h of daily use. ConclusionsDespite early diagnosis and evaluation, the pediatric SSD cohort is characterized by high rates of loss of follow-up and amplification discontinuation. Cochlear nerve deficiency is commonly seen in congenital SSD. Early specialist referral is critical for habilitation evaluation. Patients and caregivers should be educated on the significant implications of unilateral hearing loss.

Molecular characterization of Epstein-Barr virus variants detected in the oral cavity of adolescents in Cali, Colombia

ResumenIntroducción. El virus de Epstein-Barr (EBV) es un virus ubicuo y oncogénico, asociado con el desarrollo de enfermedades como la mononucleosis infecciosa, el linfoma de Burkitt, el carcinoma nasofaríngeo y otras neoplasias. Actualmente, se reconocen dos subtipos: EBV-1 y EBV- 2, que tienen diferencias genéticas con sus antígenos nucleares (Epstein-Barr Nuclear Antigens, EBNA). Debido a la gran heterogeneidad y variabilidad encontradas en la proteína LMP1 del virus, se han descrito variantes asociadas con ciertas enfermedades o con regiones geográficas específicas.Objetivo. Identificar y caracterizar molecularmente las variantes del EBV detectadas en la cavidad oral de 84 adolescentes de Cali, Colombia.Materiales y métodos. Se hizo la amplificación por reacción en cadena de la polimerasa (Polymerase Chain Reaction, PCR) convencional, así como la purificación y la secuenciación del gen EBNA3C se realizó para subtipificar el virus y del dominio C-ter de la proteína LMP1 para identificar variantes. Además, se llevó a cabo un análisis filogenético y de variantes nucleotídicas de las secuencias obtenidas comparadas con variantes patogénicas y geográficas reportadas en el GenBank (National Center for Biotechnology Information, NCBI). Resultados. El subtipo viral predominante fue el EBV-1 (79 %); el 72,6 % se agrupó con la variante patogénica Raji, derivada de linfocitos B de un paciente con linfoma de Burkitt; el 13,7 % se relacionó con una variante de origen geográfico del Mediterráneo y otro 13,7 % no se agrupó con ninguna de las variantes de referencia.Conclusiones. Este es el primer estudio que reporta variantes del gen LMP1-EBV en Cali, Colombia. Se requieren nuevos estudios para caracterizar la variante sin identificar y determinar si es patogénica o si es una variante geográfica presente exclusivamente en la ciudad.

Nicking-assisted on-loop and off-loop enzymatic cascade amplification for optomagnetic detection of a highly conserved dengue virus sequence

Applications of conventional linear ligation-rolling circle amplification (RCA) are restricted by the sophisticated operation steps and unsatisfactory picomolar-level detection limits. We herein demonstrate an RCA-based cascade amplification reaction that converts a side-reaction to secondary amplification, which improves the detection limit and simplifies the operation compared to linear ligation-RCA assays. The proposed nicking-assisted enzymatic cascade amplification (NECA) comprises an on-loop amplification reaction using circular templates to generate intermediate amplicons, and an off-loop amplification reaction using intermediate amplicons as primers for end amplicons. The whole NECA reaction is homogeneous and isothermal. Amplicons anneal to detection probes that are grafted onto magnetic nanoparticles (MNPs), such that MNP clusters form and can be detected in real-time using optomagnetic measurements. The optomagnetic sensor detects the presence and size increase of MNP clusters by optical transmission measurements in an oscillating magnetic field. A detection limit of 2 fM was achieved with a total assay time of ca. 70 min. By combining optomagnetic readouts of signal phase lag and hydrodynamic size increase of MNPs, NECA-based target quantification provided a wide dynamic detection range of ca. 4.5 orders of magnitude. Moreover, the specificity and the serum detection capability of the proposed method were investigated.

Guidelines for Impact Echo Test Signal Interpretation Based on Wavelet Packet Transform for the Detection of Pile Defects

Nonlinear amplification is typically done on velocity signals from low-strain pile integrity tests to enhance weak echoes and superimpose any peak reflections. This conventional method may sometimes fail to untangle the hidden information within the signal that is obscured by the presence of noise. In this study, a pile defect identification system based on the conventional nonlinear amplification method and the wavelet packet transform (WPT) was proposed to easily detect the presence of any geometric or material defects by identifying feature parameters. Diagnostic rules, which have been lacking in the literature, were presented to serve as a guide in interpreting decomposed signals and in analyzing various characteristics of peak waveforms that are associated with certain types of defects. In this study, the finite element method was used to simulate the impact echo test of nine cases of defective piles. To verify the proposed scheme, six data sets of the nine cases of defective piles were made, in which a total of 54 piles were analyzed. The results of the study showed that the identification method based on WPT could detect defects 87.04% of the time compared to the conventional method, which only detected defects 64.81% of the time.

Decision-making in the diagnosis of tuberculous meningitis.

Tuberculous meningitis (TBM) is the most devastating form of tuberculosis (TB) but diagnosis is difficult and delays in initiating therapy increase mortality. All currently available tests are imperfect; culture of Mycobacterium tuberculosis from the cerebrospinal fluid (CSF) is considered the most accurate test but is often negative, even when disease is present, and takes too long to be useful for immediate decision making. Rapid tests that are frequently used are conventional Ziehl-Neelsen staining and nucleic acid amplification tests such as Xpert MTB/RIF and Xpert MTB/RIF Ultra. While positive results will often confirm the diagnosis, negative tests frequently provide insufficient evidence to withhold therapy. The conventional diagnostic approach is to determine the probability of TBM using experience and intuition, based on prevalence of TB, history, examination, analysis of basic blood and CSF parameters, imaging, and rapid test results. Treatment decisions may therefore be both variable and inaccurate, depend on the experience of the clinician, and requests for tests may be inappropriate. In this article we discuss the use of Bayes' theorem and the threshold model of decision making as ways to improve testing and treatment decisions in TBM. Bayes' theorem describes the process of converting the pre-test probability of disease to the post-test probability based on test results and the threshold model guides clinicians to make rational test and treatment decisions. We discuss the advantages and limitations of using these methods and suggest that new diagnostic strategies should ultimately be tested in randomised trials.

Enhancing the Signal Power Symmetry for Optical Phase Conjugation Using Erbium-Doped-Fibre-Assisted Raman Amplification

We propose a novel dual-order backward-pumped distributed Raman amplification scheme assisted erbium-doped-fibre (EDF) providing nearly perfect signal power symmetry (>93% symmetry level) over two 50.4 km single mode fibre spans. Compared with conventional dual-order Raman schemes, this scheme only requires an additional short (25 cm) erbium-doped fibre to compensate the loss from the passive components between spans, significantly improving the overall link symmetry. Unlike a conventional hybrid Raman/EDFA approach with separate amplifier modules, the proposed scheme offers cost savings by utilizing the Raman pumps to activate the erbium-doped fibre, avoiding the need for an EDF-designated pump. In an optical transmission system with four 50.4 km fibre spans, our novel Raman scheme presented in this paper enables mid-link optical phase conjugation (OPC) to compensate up to 37 dB of nonlinear Kerr inter-signal interference. This represents a 12 dB advantage in compensation over conventional dual-order Raman amplification. Our experimental and simulated results also demonstrate that the proposed configuration provides 7 dB nonlinear threshold enhancement in a 200 Gb/s DP-16QAM 200 km inline transmission system using a mid-link OPC, exceeding the enhancement observed with the conventional dual-order Raman scheme. Our simulation results also show that the optimum Q2 factor using the proposed scheme outperforms the conventional schemes at 2000 km.

Root causality analysis at early abnormal stage using principal component analysis and multivariate Granger causality

As fault detection technologies have been developed, process fault diagnosis at early abnormal stage has come to be considered a major problem. In this work, a method to analyze the root cause of faults is developed to provide proper information at the early abnormal stage. First, principal component analysis (PCA) is used for the early detection of the process fault. Then, the contributions, from which the normal portion is removed, are decomposed by singular value decomposition (SVD) method to select the hierarchical sensors. Finally, the multivariate Granger causality (MVGC) method is used to construct the sensor causalities using the hierarchical sensors. The developed methodology is verified using the liquefied natural gas fractionation process model, which embeds a sufficient number of highly correlated sensors. The results are compared with the conventional principal component analysis method and amplification of the residual contribution method to verify the advantages of the proposed method.

Detection of Potato ring rot Pathogen Clavibacter michiganensis subsp. sepedonicus by Loop-mediated isothermal amplification (LAMP) assay

Clavibacter michiganensis subsp. sepedonicus (CMS) is an important bacterial plant pathogen causing potato ring rot disease. Rapid diagnosis of CMS is crucial because of the economic losses caused by serious harvest losses. Although there are serological tests used in the rapid diagnosis of CMS, they are not widely used because of their low sensitivity. The DNA-based PCR methods, which are highly sensitive, do not have the possibility of on-site diagnosis, especially since they require serious laboratory infrastructure. In recent years, scientists have been working on alternative amplification methods to develop DNA-based point of care (POC) diagnostic methods. Accordingly, the loop-mediated isothermal amplification (LAMP) method, which was developed in the early 2000s, provides an important convenience for DNA-based tests to use in the field. Due to the unique design of primers, more amplification products could be create in a shorter time than conventional amplification methods without needing a temperature cycle, and it can be applied with the aid of a simple heater without requiring a laboratory environment. In this study, efficient LAMP method for the detection of CMS has optimized. For device-independent detection of LAMP products, colorimetric method and LFD has used.

Impact Of TP53 Gene Promoter Methylation On Chronic Lymphocytic Leukemia Pathogenesis And Progression.

BackgroundChronic lymphocytic leukemia (CLL) is a malignant lymphoid disorder that results from the overgrowth of mature-looking lymphoid cells in the blood and lymphatic tissue. Various clinical presentations have been attributed to the disease as a result of the different underlying genetic and epigenetic alterations. The current study has been initiated to study the role of an epigenetic alteration affecting the promoter of the TP53gene on CLL pathogenesis and progression.MethodsThe current study involved 54 newly diagnosed patients presenting with CLL as well as 30 normal individuals as controls. After obtaining verbal consent, data collection was done and the blood collected from all enrolled individuals for hematological investigations as well as for molecular categorization of TP53 methylation status. Methylation-specific polymerase chain reaction (MS-PCR) technique was used to define the methylation status of the TP53 gene promoter that encompasses DNA extraction, bisulfite conversion, conventional PCR amplification, running on agarose gel and documentation. Finally, statistical analysis was done to assess any correlation of the TP53 epigenetic alteration to the disease etiology and the progression.ResultsIn the current study, all controls and 42 of 54 patients show unmethylated TP53 gene promoter; on the other hand, the methylated promoter was detected among 12 patients with a p-value of 0.001. TP53 gene promoter methylation significantly linked to reduced platelet count (p-value of 0.047) and advanced stage at presentation (p-value of 0.076). No significant differences were seen among both methylated and unmethylated TP53 promoters in relation to the age of the affected individuals, total white blood cell counts and hemoglobin level of the affected individuals.ConclusionThe current study revealed a significant correlation of TP53 gene promoter methylation to chronic lymphocytic leukemia pathogenesis and lower platelet counts.

Green Relaying With Power-Efficient Amplification Factors Over Nakagami-${m}$ Frequency-Selective Fading Channels

In this paper, a power-efficient amplification factor (PEAF) is proposed for reducing the power consumption of the relay station and improving the overall system performance in dual-hop amplify-and-forward (AF) relay networks. In comparison to the conventional amplification factor, the PEAF is designed by minimizing the total transmission power whereas maintaining the required quality of service. Moreover, in accordance with the PEAF scheme, exact closed-form expressions of the probability density function and the cumulative distribution function of the received signal-to-noise ratio are derived with one-way and two-way relaying over Nakagami- ${m}$ frequency-selective fading channels. Monte Carlo simulation is executed to verify these mathematical expressions. Simulation results show that the relay system with the proposed PEAF possesses a lower outage probability and higher energy efficiency in comparison with counterparts of the conventional variable-gain AF relaying.

Fluorometric determination of ssDNA based on functionalized magnetic microparticles and DNA supersandwich self-assemblies.

A method is described for the determination of DNA via nucleic acid amplification by using nucleic acid concatemers that result from DNA supersandwich self-assemblies (SSAs). The method employs two auxiliary probes to form self-assembled biotin SSAs. These exhibit strong fluorescence if labeled with intercalator SYBR Green I. In the presence of the target (as exemplified for a 30-mer), streptavidin is released from the surface of the functionalized magnetic microparticles (FMMPs) by competitive hybridization on the surface. However, the SSA products do not conjugate to the FMMPs. This leads to a large amount of SYBR Green I intercalated into the concatemers and eventually results in amplified fluorescence in the supernate. The SSA products can be prepared beforehand, and amplification therefore can be completed within 50min. The method is more efficient than any other conventional amplification. The detection limit for the 30-mer is 26.4 fM which is better by a factor of 10 compared to other amplification methods. Conceivably, the method can be further extended to the determination of a wide variety of targets simply by replacing the sequences of the probes. Finally, this rapid and highly sensitive method was employed for detection of Ebola virus gene (≈30-mer) and ATP in spiked serum with satisfactory results. Graphical abstract A high sensitivity and efficiency bioassay is described based on functionalized magnetic microparticles and DNA supersandwich self-assemblies.

On-chip implementation of the probabilistic quantum optical state comparison amplifier.

Propagation losses in transmission media limit the transmission distance of optical signals. In the case where the signal is made up of quantum optical states, conventional deterministic optical amplification schemes cannot be used to increase the transmission distance as the copying of an arbitrary and unknown quantum state is forbidden. One strategy that can offset propagation loss is the use of probabilistic, or non-deterministic, amplification schemes - an example of which is the state comparison amplifier. Here we report a state comparison amplifier implemented in a compact, fiber-coupled femtosecond laser-written waveguide chip as opposed to the large, bulk-optical components of previous designs. This pathfinder on-chip implementation of the quantum amplifier has resulted in several performance improvements: the polarization integrity of the written waveguides has resulted in improved visibility of the amplifier interferometers; the potential of substantially-reduced losses throughout the amplifier configuration; and a more compact and environmentally-stable amplifier which is scalable to more complex networks.

Identification of Mycoses in Developing Countries.

Extensive advances in technology offer a vast variety of diagnostic methods that save time and costs, but identification of fungal species causing human infections remains challenging in developing countries. Since the echinocandins, antifungals widely used to treat invasive mycoses, are still unavailable in developing countries where a considerable number of problematic fungal species are present, rapid and reliable identification is of paramount importance. Unaffordability, large footprints, lack of skilled personnel, and high costs associated with maintenance and infrastructure are the main factors precluding the establishment of high-precision technologies that can replace inexpensive yet time-consuming and inaccurate phenotypic methods. In addition, point-of-care lateral flow assay tests are available for the diagnosis of Aspergillus and Cryptococcus and are highly relevant for developing countries. An Aspergillus galactomannan lateral flow assay is also now available. Real-time PCR remains difficult to standardize and is not widespread in countries with limited resources. Isothermal and conventional PCR-based amplification assays may be alternative solutions. The combination of real-time PCR and serological assays can significantly increase diagnostic efficiency. However, this approach is too expensive for medical institutions in developing countries. Further advances in next-generation sequencing and other innovative technologies such as clustered regularly interspaced short palindromic repeats (CRISPR)-based diagnostic tools may lead to efficient, alternate methods that can be used in point-of-care assays, which may supplement or replace some of the current technologies and improve the diagnostics of fungal infections in developing countries.

An innovative approach for performance enhancement of 320 Gbps free space optical communication system over turbulent channel

Free space optical (FSO) communication systems have recently gained huge attention as possible last mile solution in delivering high speed data services for terrestrial applications. However the FSO link performance, particularly the link range is significantly limited by the severity of atmospheric adversities affecting the channel. In this paper we advocate the use of multi-hop relay techniques to transmit wavelength division multiplexed (WDM) signal over the FSO channel. Since weather induced impairments in FSO links are distance dependent phenomena, hence relay transmission allows substantial performance enhancement by alleviating channel losses while, WDM provides cost effective solution in improving the transmission capacity. With aggregate link losses as high as 40 dB/km, the proposed 32 channel—10 Gbps (320 Gbps) FSO link has been evaluated by comparing bit error rate (BER) performances and eye patterns over different turbulent regimes. Gain optimized EDFA amplification and conventional electrical amplification have been employed to realize amplify-and-forward (A–F) multi-hop transmission in the proposed link with the former delivering more inspiring BER performance of over the latter. Our simulation results indicate that for receiver SNR of 35 dB, BER improvement up to five orders of magnitude can achieved using triple relay FSO link in contrast to direct link operating under similar conditions. Additionally, it is also observed during the analysis that for target BER of 10−5, incorporation of triple relay enhances the link range by approximately 1200 m over direct link. However on the flip side, our investigations also revealed that as the number of relay nodes is increased, the SNR gain for specified BER does increase but the magnitude of gain declines. The proposed link was designed and investigated using OptiSystem™ 14.2.