Performance and usefulness of a novel automated immunoassay HISCL SARS-CoV-2 Antigen assay kit for the diagnosis of COVID-19

Here, we aimed to evaluate the clinical performance of a novel automated immunoassay HISCL SARS-CoV-2 Antigen assay kit designed to detect the nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This kit comprises automated chemiluminescence detection systems.
Western blot analysis confirmed that anti-SARS-CoV antibodies detected SARS-CoV-2N proteins. The best cut-off index was determined Bio Med Frontiers , and clinical performance was tested using 115 serum samples obtained from 46 patients with coronavirus disease 2019 (COVID-19) and 69 individuals who tested negative for COVID-19 through reverse transcription quantitative polymerase chain reaction (RT-qPCR).
The HISCL Antigen assay kit showed a sensitivity of 95.4% and 16.6% in samples with copy numbers > 100 and < 99, respectively.
The kit did not cross-react with human coronaviruses causing seasonal common cold and influenza, and none of the 69 individuals without COVID-19 were diagnosed with positive results.
Importantly, 81.8% of the samples with low virus load (< 50 copy numbers) were diagnosed as negative. Thus, using HISCL antigen assay kits may reduce overdiagnosis compared with RT-qPCR tests.
The rapid and high-throughput HISCL SARS-CoV-2 Antigen assay kit developed here proved suitable for screening infectious COVID-19 and may help control the pandemic.

Commercial Simplex and Multiplex PCR Assays for the Detection of Intestinal Parasites Giardia intestinalisEntamoeba spp., and Cryptosporidium spp.: Comparative Evaluation of Seven Commercial PCR Kits with Routine In-House Simplex PCR Assays

  • Nowadays, many commercial kits allowing the detection of digestive parasites by DNA amplification methods have been developed, including simplex PCR assays (SimpPCRa) allowing the identification of a single parasite, and multiplex PCR assays (MultPCRa) allowing the identification of several parasites at once.
  • Thus, aimed at improving the diagnosis of intestinal protozoal infections, it is essential to evaluate the performances of these new tools.
  • A total of 174 DNA samples collected between 2007 and 2017 were retrospectively included in this study. Performances of four commercial SimpPCRa (i.e., CerTest-VIASURETM) and three MultPCRa (i.e., CerTest-VIASURETM, FAST-TRACK-Diagnostics-FTD-Stool-ParasiteTM and DIAGENODE-Gastroenteritis/Parasite-panel-ITM) were evaluated for the detection of Cryptosporidium spp., Entamoeba spp., and Giardia intestinalis in stool samples compared to our routinely used in-house SimpPCRa.
  • Globally, Our Provider the SimpPCRa showed better sensitivity/specificity for the detection of G. intestinalisE. histolyticaE. dispar, and Cryptosporidium spp. (i.e., 96.9/93.6%; 100/100%; 95.5/100%; and 100/99.3%, respectively), compared to the three commercial MultPCRa tested.
  • All in all, we showed that MultPCRa offer an interesting alternative for the detection of protozoans in stool samples depending on the clinical context.

Real-Time PCR Assay for the Detection of Dermatophytes: Comparison between an In-House Method and a Commercial Kit for the Diagnosis of Dermatophytoses in Patients from Dakar, Senegal

PCR assays have been developed for the diagnosis of dermatophytes, yet data in African populations are scarce.
This study aimed to compare two PCR assays for the diagnosis of dermatophytosis in outpatients at the Aristide Le Dantec University Hospital in Dakar, Senegal.
 A total of 105 samples, including 24 skin, 19 nail and 62 hair samples collected from 99 patients were included in this study. Each sample was subjected to conventional diagnosis (CD), including direct microscopy and culture, and two real-time PCR assays: one in-house (IH)-PCR, used at the University Hospital of Marseille and the Eurobio Scientific commercial kit (CK): designed for the specific detection of six dermatophytes not including Microsporum audouinii.
 Of the 105 specimens, 24.8%, 36.2% and 20% were positive by CD, IH-PCR and CK-PCR, respectively. The IH-PCR and CK-PCR exhibited 88.9% and 65.4% sensitivity, respectively.
With a 36.6 diagnostic odd ratio and 1.41 needed to diagnose, the IH-PCR displayed better diagnostic indices than the CK-PCR.
It is notable that, when considering the species that it claims to detect, when it came to skin and nail samples, CK-PCR sensitivity increased to 77%.
The pan-dermatophyte IH-PCR performed better in the diagnosis of dermatophytosis in this African population than the CK-PCR, which is not designed to detect M. audouinii.
Nevertheless, both assays exhibited similarly good diagnostic indices for tinea corporis and tinea unguium, both of which are localisations where M. audouinii is more rarely involved than in tinea capitis.

A large staghorn stone diagnosed and managed in an asymptomatic patient using the “Kidney Injury Test (Kit)” spot urine assay: A case report

The Kidney Injury Test (KIT) Stone-Score provides an objective measure of stone burden. Unlike urinary supersaturation the KIT Stone-Scores assess underlying stone disease rather than urinary solute composition.
We report a case of a 43-year-old woman with no history of nephrolithiasis who underwent an elective, voluntary KIT assay and was diagnosed with a large staghorn renal stone after an unanticipated markedly elevated score.
This clinical scenario highlights the potential future use of the non-invasive urinary KIT assay as a reliable non-invasive tool to detect and monitor urinary stone disease.

Evaluation of the concordance between GluN1-GluN2 heteromer live-cell-based assay and GluN1 monomer biochip kit assay on anti-NMDAR autoantibody detection

  • Anti-N-methyl-d-aspartate receptor (NMDAR) antibodies are most frequently detected in autoantibody-related autoimmune encephalitis.
  • Anti-NMDAR encephalitis mainly affects young women with ovarian teratoma, including acute to subacute onset of psychosis, seizures, consciousness disturbance, dyskinetic involuntary movements, autonomic dysfunction, and others.
  • Diagnosis is based on the detection of anti-NMDAR autoantibodies in cerebrospinal fluid (CSF). The autoantibody recognizes the conformational epitope of the NMDA receptor.
  • NMDA receptors contain hetero-tetramers of GluN1 (NR1) and GluN2/3 (NR2/3), in which GluN1 is essential to form functional receptors on the synaptic membrane in the brain.
  • Thus, the autoantibodies are detected using neurons or culture cells expressing conformational receptors on their cell membrane, the natural form in the brain.
  • The antibodies detected using artificial GluN1 monosubunit expressing cells as the antigens have been widely used for anti-NMDAR-antibody test.
  • In the present study two detection systems were compared, a live-cell-based assay using human embryonic kidney (HEK) 293 cells expressing both of GluN1 and GluN2B, and a commercially available GluN1-monotransfected HEK cell biochip system.
  • As the result, both the methods were equivalent, and the clinical features of both groups were similar, suggesting both tests have equal clinical significance.

Enzymatic characterization of D-lactate dehydrogenase and application in alanine aminotransferase activity assay kit

D-lactate dehydrogenase (D-LDH) is widely used for the clinical detection of alanine aminotransferase (ALT) activity. It is a key enzyme in ALT detection kits, and its enzymatic properties directly determine sensitivity and accuracy of such kits.
In this study, D-lactate dehydrogenase (WP_011543503, ldLDH) coding sequence derived from Lactobacillus delbrueckii was obtained from the NCBI database by gene mining. LdLDH was expressed and purified in Escherichia coli, and its enzyme activity, kinetic parameters, optimum temperature, and pH were characterized.
Furthermore, stabilizers, including sugars, polyols, amino acids, certain salts, proteins, and polymers, were screened to improve stability of ldLDH during freeze-drying and storage.

Frit Kit

FRIT-KIT Next Advance 1each 124 EUR

Column Packing Kit

PACK-KIT Next Advance 1pack 1035 EUR

PCR Mycoplasma Detection Kit

M034-Kit TOKU-E Kit 266 EUR

Cas9 Protein and T7 gRNA SmartNuclease Synthesis Kit

CAS400A-KIT SBI 1 kit (10 rxn) 1110 EUR

CMV-hspCas9-T2A-Puro SmartNuclease Lentivector Plasmid + LentiStarter Packaging Kit

CASLV100PA-KIT SBI 1 Kit 1132 EUR

CMV-hspCas9-EF1-GFP SmartNuclease Lentivector Plasmid + LentiStarter Packaging Kit

CASLV105PA-KIT SBI 1 Kit 1132 EUR

MSCV-hspCas9-T2A-Puro SmartNuclease Lentivector Plasmid + LentiStarter Packaging Kit

CASLV120PA-KIT SBI 1 Kit 1132 EUR

MSCV-hspCas9-EF1-GFP SmartNuclease Lentivector Plasmid + LentiStarter Packaging Kit

CASLV125PA-KIT SBI 1 Kit 1132 EUR

Multiplex gRNA Kit + EF1-T7-hspCas9-H1-gRNA linearized SmartNuclease vector

CAS700A-KIT SBI 10 rxn 1132 EUR

Multiplex gRNA Kit + CAG-T7-hspCas9-H1-gRNA linearized SmartNuclease vector

CAS720A-KIT SBI 10 rxn 1132 EUR

Multiplex gRNA Kit + CMV-T7-hspCas9-H1-gRNA linearized SmartNuclease vector

CAS740A-KIT SBI 10 rxn 1132 EUR

T7 gRNA SmartNuclease Synthesis Kit (includes CAS510A-1 & T7 IVT synthesis reagents)

CAS510A-KIT SBI 1 Kit 805 EUR
Finally, a kit based on ldLDH was tested to determine whether the enzyme had potential clinical applications. The results showed that ldLDH had a specific activity of 1,864 U/mg, Km value of 1.34 mM, optimal reaction temperature of 55°C, and an optimal pH between 7.0 and 7.5.
When sucrose or asparagine was used as a stabilizer, freeze-dried ldLDH remained stable at 37°C for > 2 months without significant loss of enzymatic activity.
These results indicated that ldLDH possesses high activity and stability. Test results using the ALT assay kit prepared with ldLDH were consistent with those of commercial kits, with a relative deviation <5%. These results indicated that ldLDH met the primary requirements for ALT assays, laying a foundation for the development of new ALT kits with potential clinical applications.

Leave a Comment