Head-to-head comparison of Enzyme Linked Immunosorbent Assay (ELISA) and Enhanced Chemiluminescence Immunoassay (ECLIA) for the detection of Transfusion Transmitted Disease (TTD) Markers; HIV, HCV and HBV in blood donors, in India

Potential-Resolved Electrochemiluminescence Multiplex Immunoassay for Florfenicol and Chloramphenicol in a Single Sample

The simultaneous detection of multiple antibiotic residues in food is of great significance for food safety. In this work, a novel dual-potential electrochemiluminescence (ECL) immunoassay was designed for the simultaneous detection of chloramphenicol and fluorfenicol residues in food. Ru@MOF was used as an anodic probe, and SnS2 QDs-PEI-Au-MoS2 was used as a cathodic probe. Notably, the coreactant for both luminophores was K2S2O8, avoiding interactions caused by different kinds of coreactants. Au nanoparticles functionalized with a nitrogen- and sulfur-doped graphene oxide-modified glassy carbon electrode to improve the electron transfer efficiency and provide a larger surface area for immobilization of antigen. The linear range for the detection of florfenicol was determined to be 0.1-1000 ng mL-1 with a detection limit of 0.03 ng mL-1, and the linear range for the detection of chloramphenicol was 0.01-1000 ng mL-1 with a detection limit of 3.2 pg mL-1 by recording the ECL responses at two different excitation potentials. The proposed immunoassay achieved a more stable recovery in the detection of actual samples and provided a new analytical method for the simultaneous detection of florfenicol and chloramphenicol residues with high sensitivity and specificity.

Viral Diagnosis of Hepatitis B and Delta: What We Know and What Is Still Required? Specific Focus on Low- and Middle-Income Countries

To achieve the World Health Organization's (WHO) goals of eradicating viral hepatitis globally by 2030, the regional prevalence and epidemiology of hepatitis B virus (HBV) and hepatitis delta virus (HDV) coinfection must be known in order to implement preventiveon and treatment strategies. HBV/HDV coinfection is considered the most severe form of vira l hepatitis due to it's rapid progression towards cirrhosis, hepatocellular carcinoma, and liver-related death. The role of simplified diagnosticsis tools for screening and monitoring HBV/HDV-coinfected patients is crucial. Many sophisticated tools for diagnoses have been developed for detection of HBV alone as well as HBV/HDV coinfection. However, these advanced techniques are not widely available in low-income countries and there is no standardization for HDV detection assays, which are used for monitoring the response to antiviral therapy. More accessible and affordable alternative methods, such as rapid diagnostic tests (RDTs), are being developed and validated for equipment-free and specific detection of HBV and HDV. This review will provide some insight into both existing and diagnosis tools under development, their applicability in developing countries and how they could increase screening, patient monitoring and treatment eligibility.

Prevalence of hepatitis B & C infections in prospective blood donors deferred due to history of jaundice

Background & objectives

As per national guidelines, prospective blood donors with a history of jaundice of unknown cause are deferred permanently to prevent the transmission of hepatitis B and C. The validity of this guideline was tested by comparing prevalence rates of hepatitis B and C in prospective blood donors deferred due to a history of jaundice, with that of donors who were found fit.

Methods

Blood samples of 212 consecutive donors (male, n=203) deferred due to a history of jaundice were studied for hepatitis B and C by rapid test kits as well as by chemiluminescence (n=115) or ELISA (n=97). Consecutive healthy donors (n=549; male, n=518) were also studied by ELISA (n=266) or chemiluminescence (n=283).

Results

The cumulative prevalence detected by rapid test kit and ELISA/chemiluminescence tests of hepatitis B (n=10) and C (n=2) among donors deferred due to a history of jaundice (n=212) was 5.7 per cent [95% confidence interval (CI): 2.9, 9.9]. The prevalence of reactive results among healthy donors (n=549) by ELISA/chemiluminescence tests was 3.3 per cent (95% CI: 1.9, 5.2), which included hepatitis B (n=15) and hepatitis C (n=3) cases. Compared to healthy donors, the odds of seropositivity among jaundice-deferred donors was 1.7 (95% CI: 0.8, 3.6), P=0.15. For rapid test-negative deferred donors, the odds of seropositivity by ELISA/chemiluminescence declined to 0.4 (0.1, 1.5), P=0.19.

Interpretation & conclusions

The prevalence rates of hepatitis B and C in prospective blood donors deferred due to a history of jaundice of unknown aetiology did not differ significantly from that in healthy donors. The current practice of permanently deferring such donors depletes valuable donor pool. A strategy of rejecting only those donors who are found reactive on pre-donation testing by rapid test needs further validation.

Development of a Chemiluminescence Assay for Total N-Terminal Propeptide of Type I Collagen and Its Evaluation in Lung Transplantation

Serum P1NP, one of the important biomarkers for bone turnover, is commonly used for the prediction of bone fracture and the prognosis of osteoporosis after therapy. We developed a P1NP chemiluminescence assay and evaluated changes in bone metabolism markers in lung transplant patients. The screened 2 P1NP antibodies with constructed antigens and α-1 chain antigens expressed by the Corynebacterium glutamate expression system were applied into assay development. The assay performance was evaluated to examine the reliability. A normal Q-Q plot was used to establish male reference interval. Changes of bone metabolism markers before and after lung transplantation in 19 patients were evaluated. The linear factor R of P1NP reagent was greater than 0.99. The limit of detection was 3.32 ng/ml. The precision of the three batches of P1NP reagents was lower than 8%. Method comparison with Roche P1NP reagent showed that the correlation coefficient R ² was 0.91. In the monitoring of bone mass in a short time, bone metabolism markers can better indicate the change of bone mass, while the traditional bone mineral density detection is lagging behind the bone metabolism markers. P1NP and β-CrossLap to bone mass change in patients after lung transplantation, and P1NP and β-CrossLap are very good clinical markers for bone mass monitoring.

Flexible paper-based Ni-MOF composite/AuNPs/CNTs film electrode for HIV DNA detection

It is very important to develop a rapid, simple, low cost point-of-care (POC) method for the early diagnosis of pathogens. In this work, a flexible paper-based electrode based on nickel metal-organic framework (Ni-MOF) composite/Au nanoparticles/carbon nanotubes/polyvinyl alcohol (Ni-Au composite/CNT/PVA) was constructed to detect target human immunodeficiency virus (HIV) DNA by DNA hybridization using methylene blue (MB) as a redox indicator. The CNT/PVA and Ni-Au composite were deposited on the cellulose membrane by vacuum filtration and drop-coating method in turn to obtain Ni-Au composite/CNT/PVA (CCP) film electrode. Compared to the CNT/PVA film electrode, CCP film electrode makes a higher loading of the probe DNA for its large specific surface area and conjugated π-electron system that can provide hydrogen bond sources to achieve interactions between MOF and single-stranded DNA, which improves the sensitivity for detecting target DNA. The variation of peak current for MB molecules adsorbed onto DNA before and after hybridization with HIV DNA was monitored. Electrochemical results proved that the CCP film maintained stable electrochemical property even after bending 200 times or stretching under different strains from 0% to 20%. The flexible paper electrode showed excellent sensing performance with a linear range of 10 nM-1 μM and a low detection limit of 0.13 nM. The target HIV DNA was successfully detected even in complex serum samples using the flexible CCP film electrode. Therefore, the simple and inexpensive flexible paper-based MOF composite film electrode can also be utilized for other pathogens POC diagnosis.