Antiapoptosis Engineering for Improved Protein Production from CHO Cells.

Improving the time integral of viable cell concentration by overcoming cell death, namely apoptosis, is one of the most widely used strategies for the efficient production of therapeutic proteins. By establishing stable cell lines that overexpress antiapoptotic genes or downregulate proapoptotic genes, the final product yields can be enhanced as cells become more resistant to environmental stresses. From the selection of high-expressing clones to verification of antiapoptotic activity, the method to construct a stable antiapoptotic cell line is discussed in this chapter.

Role of in-situ electrical stimulation on early-stage mineralization and in-vitro osteogenesis of electroactive bioactive glass composites.

Bioactive glass (BAG) has emerged as an effective bone graft substitute due to its diverse qualities of biocompatibility, bioactivity, osteoblast adhesion and enhanced revascularization. However, inferior osteogenic capacity of BAG compared to autologous bone grafts continues to limiting it's wide-spread clinical applications towards repairing of bone fractures and healing. In this study, we have fabricated BAG composites with 0.5 to 2 wt% bismuth ferrite (BF, a multiferroic material) with an aim to generate in-situ electrical charges pertinent to early-stage bone regeneration thus mimicking natural bone, which is a piezoelectric material. The fabricated BAG composites were characterised in terms of microstructures, phase analysis, remanent polarization, wettability and subsequently evaluated for in vitro cell proliferation and osteogenesis with and without magnetic field exposure (200 mT, 30 min./day). Pre-osteoblast cells from mice (MC3T3-E1) seeded on these composites exhibited excellent cell growth without any cytotoxicity, which is further supported by FITC/DAPI staining and a live/dead assay. The results of Alizarin Red S assay and increased levels of Alkaline Phosphatase (ALP) activity, at 21 days of culture, suggest that the BAG-BF composites promote in vitro osteogenic differentiation of pre-osteoblast cells. The enhanced osteogenesis of BAG-BF composites was also confirmed through qRT-PCR analysis, which showed rapid upregulation of osteoblastogenic specific genes namely RunX-2, Collagen-1, Bone Sialo Protein, and ALP after 21 days. Additionally, the osteogenic differentiation was assessed by the Western Blot technique, which revealed significantly higher band intensity of osteogenic markers in BAG-1.5 BF and BAG-2 BF composites than pure BAG. These findings clearly demonstrate that in-situ electrical stimulation and osteoconductive capacity of BF reinforced BAG composites have positive impact on osteoblast cell development, bone formation, and healing.

A guide to selecting high-performing antibodies for CSNK2A1 (UniProt ID: P68400) for use in western blot, immunoprecipitation and immunofluorescence.

Casein kinase II subunit alpha (CSNK2A1), a serine/threonine kinase, phosphorylates multiple protein substrates and is involved in diverse cellular and biological processes. Implicated in various human diseases, high-performing antibodies would help evaluate its potential as a therapeutic target and benefit the scientific community. In this study, we have characterized ten CSNK2A1 commercial antibodies for western blot, immunoprecipitation, and immunofluorescence using a standardized experimental protocol based on comparing read-outs in knockout cell lines and isogenic parental controls. These studies are part of a larger, collaborative initiative seeking to address antibody reproducibility issues by characterizing commercially available antibodies for human proteins and publishing the results openly as a resource for the scientific community. While use of antibodies and protocols vary between laboratories, we encourage readers to use this report as a guide to select the most appropriate antibodies for their specific needs.

A comprehensive and single-use foot-and-mouth disease sero-surveillance prototype employing rationally designed multiple viral antigens.

Foot-and-mouth disease (FMD) is a great havoc in agri-business-based countries like Bangladesh, for which existing detection system limits the identification and differentiation of serotypes. In this study, an engineered platform was introduced incorporating serotype-specific FMDV VP1 (structural), serotype-independent VP2 (structural) and 3AB (non-structural) proteins for holistic detection. VP1 sequences were engineered combining sequences of BAN/TA/Dh-301/2016 (serotype O), BAN/CH/Sa-304/2016 (serotype A) and BAN/DH/Sa-318/2016 (serotype Asia1). Consensus 3AB sequence was constructed from the selected prevalent viral genomes. Both VP1 and 3AB along with designed VP2 sequences were optimized for codon usage bias, stable mRNA, secondary and tertiary protein structure. Proteins were synthesized in pET-21a ( +) plasmid vector followed by transformation of Escherichia coli BL21(DE3) and IPTG-induced- expression. The western blot analysis of engineered proteins showed that purified VP1 prominently bound to anti-VP1 antibodies in vaccinated sera, whereas 3AB and VP2 bound anti-3AB and anti-VP2 antibodies, respectively from infected cattle sera, all previously collected during epidemiological investigation. Furthermore, dot blot hybridization confirmed efficient antibody capture ability of the membrane-immobilized proteins. This holistic diagnostic platform justifies a comprehensive prototype diagnostic kit that would be cost-effective and efficient for serotype specific and non-specific FMDV sero-surveillance.

An Analysis of Genetic Polymorphisms in 76 Genes Related to the Development of Ovarian Tumors of Different Aggressiveness.

Borderline ovarian tumors (BOTS) are rare neoplasms of intermediate aggressiveness between cystadenomas and low-grade ovarian cancers (lgOvCa), which they share some molecular resemblances with. In contrast to the most frequent and well-described high-grade ovarian carcinomas (hgOvCa), the molecular background of BOTS and lgOvCa is less thoroughly characterized. Here, we aimed to analyze genetic variants in crucial tumor suppressors and oncogenes in BOTS (with or without the BRAF V600E mutation), lgOvCa, and hgOvCa in two gene panels using next-generation sequencing. Then, we verified the existence of selected polymorphisms by Sanger sequencing. Finally, Western blot analyses were carried out to check the impact of the selected polymorphisms on the expression of the corresponding proteins. Our study contributes to the molecular characterization of ovarian neoplasms, demonstrating divergent polymorphic patterns pointing to distinct signaling pathways engaged in their development. Certain mutations seem to play an important role in BOTS without the BRAF V600E variant (KRAS) and in lgOvCa (KRAS and NRAS), but not in hgOvCa. Additionally, based on multivariable regression analyses, potential biomarkers in BOTS (PARP1) and hgOvCa (FANCI, BRCA2, TSC2, FANCF) were identified. Noteworthy, for some of the analyzed genes, such as FANCI, FANCD2, and FANCI, FANCF, TSC2, the status of BRCA1/2 and TP53, respectively, turned out to be crucial. Our results shed new light on the similarities and differences in the polymorphic patterns between ovarian tumors of diverse aggressiveness. Furthermore, the biomarkers identified herein are of potential use as predictors of the prognosis and/or response to therapy.

Acute stress induces different changes on the expression of CB1 receptors in the hippocampus of two lines of male rats differing in their response to stressors.

The stress-induced alterations in cognitive processes and psychiatric disorders can be accelerated when acute stressors challenge the hippocampal functions. To address this issue, we used Western Blot (WB) and immunohistochemistry assays to investigate the impact of acute forced swimming (FS) on the expression of the CB1 cannabinoid receptors (CB1R) in the hippocampus (HC) of the male outbred Roman High- (RHA) and Low-Avoidance (RLA) rat lines, one of the most validated genetic models for the study of behavior related to fear/anxiety and stress-induced depression. The distinct responses to FS confirmed the different behavioral strategies displayed by the two phenotypes when exposed to stressors, with RLA and RHA rats displaying reactive vs. proactive coping, respectively. In control rats, the WB analysis showed lower hippocampal CB1R relative levels in the RLA rats than in their RHA counterparts. After FS, RLA rats showed increased CB1R levels in the dorsal HC (dHC) vs. no change in the ventral HC (vHC), while RHA rats displayed no change in the dHC vs. a decrease in the vHC. In the tissue sections from dHC, FS elicited an increment over the control level of CB1R-like immunoreactivity (LI) in the CA1 and CA3 sectors of the Ammon's horn of RLA rats, while in RHA rats the density of CB1R-LI increased only in the CA1 sector. In tissue sections from the vHC, FS caused an increase over the control values of CB1R-LI only in the CA1 sector of the RLA rats and a decrement of the CB1R-LI in the CA1 sector and the dentate gyrus of the control RHA rats. This study shows for the first time that, in baseline conditions, the CB1Rs are present in the dHC and the vHC of the Roman rat lines with a different distribution along the septo-temporal extension of the HC and that the FS induces rapid and distinct changes in the hippocampal expression of CB1R of RLA vs. RLA rats, in keeping with the view that endocannabinoid signaling may contribute to the molecular mechanisms that regulate the different responses of the dHC vs. the vHC to aversive situations in male Roman rats. Our results also provide evidence supporting the involvement of CB1R in the molecular underpinnings of the susceptibility of RLA rats and the resistance of RHA rats to stress-induced depression-like behavior.

Screening and expression validation of key proteins for secondary hair follicle growth in cashmere goats based on iTRAQ quantitative proteomics technology.

Background: The growth of secondary hair follicles (SHFs) in cashmere goats has periodic changes, including telogen, anagen, and catagen, during which proteins play important roles as the executor of life activities. Results: In this study, the skin tissues of cashmere goats at three different growth stages of SHFs were collected for proteome sequencing and validation experiments. Through protein differential expression analysis and time series analysis, FKBP prolyl isomerase 10 (FKBP10) and fibrillin 2 (FBN2) were screened as the key proteins for SHF cycle growth of cashmere goats, and albumin (ALB), collagen type I alpha 1 chain (COL1A1) and elastin (ELN) were predicted to be their interacting proteins. The results of quantitative real-time PCR (qRT-PCR), western blot, and immunohistochemistry experiments showed that the mRNA and protein expression levels of FKBP10, FBN2, COL1A1, ELN and ALB were higher in anagen and lower in telogen. They were all highly expressed in the outer root sheath of SHFs in anagen. Conclusion: FKBP10, FBN2, COL1A1, ELN, and ALB can promote the growth of SHFs in cashmere goats. This study lays the foundation for analyzing the growth cycle regulatory mechanism of SHFs in cashmere goats, and provides new ideas for further improving cashmere yield and quality.

A guide to selecting high-performing antibodies for PLC-gamma-2 for use in Western Blot, immunoprecipitation and immunofluorescence.

Phosphatidylinositol-specific phospholipase C gamma 2 (PLC-gamma-2) is an enzyme that regulates the function of immune cells. PLC-gamma-2 has been implicated in neurodegenerative and autoimmune disorders, yet investigation of this protein has been limited by a lack of independently characterized antibodies. Here we have characterized eleven PLC-gamma-2 commercial antibodies for use in Western Blot, immunoprecipitation, and immunofluorescence using a standardized experimental protocol based on comparing read-outs in knockout cell lines and isogenic parental controls. These studies are part of a larger, collaborative initiative seeking to address antibody reproducibility issues by characterizing commercially available antibodies for human proteins and publishing the results openly as a resource for the scientific community. While use of antibodies and protocols vary between laboratories, we encourage readers to use this report as a guide to select the most appropriate antibodies for their specific needs.

FGF23 and Cell Stress in SaOS-2 Cells-A Model Reflecting X-Linked Hypophosphatemia Dynamics.

Our study investigates the impact of FGF23 overexpression on SaOS-2 cells to elucidate its role in cellular stress and morphology, contributing to the understanding of skeletal pathologies like X-linked hypophosphatemia (XLH). Using transmission electron microscopy and protein analysis (Western blot), we analyzed the rough endoplasmic reticulum (rER) and mitochondria in SaOS-2 cells with FGF23 overexpression compared to controls. We found significant morphological changes, including enlarged and elongated rER and mitochondria, with increased contact zones, suggesting enhanced interaction and adaptation to elevated protein synthesis and secretion demands. Additionally, we observed higher apoptosis rates of the cells after 24-72 h in vitro and upregulated proteins associated with ER stress and apoptosis, such as CHOP, XBP1 (spliced and unspliced), GRP94, eIF2α, and BAX. These findings indicate a robust activation of the unfolded protein response (UPR) and apoptotic pathways due to FGF23 overexpression. Our results highlight the critical role of ER and mitochondrial interactions in cellular stress responses and provide new insights into the mechanistic link between FGF23 signaling and cellular homeostasis. In conclusion, our study underscores the importance of analyzing UPR-related pathways in the development of therapeutic strategies for skeletal and systemic diseases and contributes to a broader understanding of diseases like XLH.

Production and characterization of a panel of anti-mouse placenta-specific protein 1 (plac1) monoclonal antibodies.

Placenta-Specific Protein 1 (PLAC1) is essential for normal placental and embryonic development. It is widely expressed in various types of cancer cells. We produced a panel of anti-mouse plac1 monoclonal antibodies (mAbs) with different applications. Two recombinant proteins were produced containing either the extracellular domain (ED) plus tetanus toxin P2, P30, pan-DR epitope (PADRE), and KDEL3 (main plac1) or ED plus KDEL3 (control plac1). Recombinant proteins were used for immunization and screening. Positive clones were selected by ELISA and flow cytometry. Purified mAbs were tested by ELISA, WB, flow cytometry, immunohistochemistry (IHC), and immunofluorescent (IF). A combination of bioinformatics tools was used to predict the target epitope(s) of the mAbs. Eight anti-mouse plac1 mAbs (all IgG1/κ1) were generated, all reacting with high affinity in ELISA. Seven clones recognized plac1 in both reduced and non-reduced Western blots, while one only recognized the non-reduced form. Cross-inhibition ELISA revealed that all mAbs recognized overlapping epitopes with a shared motif except for 5C9. Four clones reacted with the native antigen in flow cytometry, but none were functional in IF or IHC staining. The produced multifunctional mAbs can be used to investigate different aspects of PLAC1 biology in reproduction and cancer.

Adropin Is Expressed in Pancreatic Islet Cells and Reduces Glucagon Release in Diabetes Mellitus.

Diabetes mellitus affects 537 million adults around the world. Adropin is expressed in different cell types. Our aim was to investigate the cellular localization in the endocrine pancreas and its effect on modulating pancreatic endocrine hormone release in streptozotocin (STZ)-induced diabetic rats. Adropin expression in the pancreas was investigated in normal and diabetic rats using immunohistochemistry and immunoelectron microscopy. Serum levels of insulin, glucagon pancreatic polypeptide (PP), and somatostatin were measured using a Luminex® χMAP (Magpix®) analyzer. Pancreatic endocrine hormone levels in INS-1 832/3 rat insulinoma cells, as well as pancreatic tissue fragments of normal and diabetic rats treated with different concentrations of adropin (10-6, 10-9, and 10-12 M), were measured using ELISA. Adropin was colocalized with cells producing either insulin, glucagon, or PP. Adropin treatment reduced the number of glucagon-secreting alpha cells and suppressed glucagon release from the pancreas. The serum levels of GLP-1 and amylin were significantly increased after treatment with adropin. Our study indicates a potential role of adropin in modulating glucagon secretion in animal models of diabetes mellitus.

Combination of Metabolomics, Lipidomics, and Molecular Biology for the Investigation of the Metabolic Disturbance of Short-Term Administration of Emodin.

Emodin, a natural anthraquinone derivative, is an active ingredient in many Chinese traditional herbs. Interestingly, although it is generally considered to possess hepatoprotective activity, some studies have also reported that it has a certain degree of hepatotoxicity. Additionally, the underlying metabolic regulation of emodin remains uncertain. Therefore, we conducted a nontargeted metabolomic study based on UHPLC/Q-Orbitrap-MS and NMR. Data are available via ProteomeXchange with the identifier PXD055000. The results indicated a close association between the short-term administration of emodin and lipid metabolism. Moreover, a lipidomics investigation utilizing QTRAP 6500+ UHPLC-MS/MS was conducted, with a focus on determining the position of C═C double bonds in unsaturated lipids based on Paternò-Büchi (PB) reaction to discover the metabolic disturbance more precisely. Specifically, lipidomics revealed elevated levels of free fatty acids (FFA) alongside notable reductions in sphingomyelin (SM) and triacylglycerol (TAG) levels. Furthermore, the combination of PB reaction and molecular biology results indicated that short-term administration of emodin may lead to the accumulation of n-6 polyunsaturated fatty acids by up-regulating the expression of FASN, stearyl CoA desaturase 1 (SCD1), and cytosolic phospholipase A 2 (cPLA2). Simultaneously, up-regulation of cyclooxygenase-2 (Cox-2) expression was observed, potentially fostering the production of prostaglandin E2 (PGE2) and subsequent inflammation.

A guide to selecting high-performing antibodies for Protein-glutamine gamma-glutamyltransferase 2 (TGM2) for use in western blot, immunoprecipitation and immunofluorescence.

Protein-glutamine gamma-glutamyltransferase 2 (TGM2) is a Ca 2+ dependent enzyme that catalyzes transglutaminase cross-linking modifications. TGM2 is involved in various diseases, either in a protective or contributory manner, making it a crucial protein to study and determine its therapeutic potential. Identifying high-performing TGM2 antibodies would facilitate these investigations. Here we have characterized seventeen TGM2 commercial antibodies for western blot and sixteen for immunoprecipitation, and immunofluorescence. The implemented standardized experimental protocol is based on comparing read-outs in knockout cell lines against their isogenic parental controls. This study is part of a larger, collaborative initiative seeking to address antibody reproducibility issues by characterizing commercially available antibodies for human proteins and publishing the results openly as a resource for the scientific community. While the use of antibodies and protocols vary between laboratories, we encourage readers to use this report as a guide to select the most appropriate antibodies for their specific needs.

A guide to selecting high-performing antibodies for Huntingtin (UniProt ID: P42858) for use in western blot, immunoprecipitation, and immunofluorescence.

Huntingtin encodes a 3144 amino acid protein, with a polyglutamine repeat tract at the N-terminus. Expansion of this repeat tract above a pathogenic threshold of 36 repeats is the causative mutation of Huntington's disease, a neurodegenerative disorder characterized by loss of striatal neurons. Here we have characterized twenty Huntingtin commercial antibodies for western blot, immunoprecipitation, and immunofluorescence using a standardized experimental protocol based on comparing read-outs in knockout cell lines and isogenic parental controls. These studies are part of a larger, collaborative initiative seeking to address antibody reproducibility issues by characterizing commercially available antibodies for human proteins and publishing the results openly as a resource for the scientific community. While use of antibodies and protocols vary between laboratories, we encourage readers to use this report as a guide to select the most appropriate antibodies for their specific needs.

Improving rigor and reproducibility in western blot experiments with the blotRig analysis.

Western blot is a popular biomolecular analysis method for measuring the relative quantities of independent proteins in complex biological samples. However, variability in quantitative western blot data analysis poses a challenge in designing reproducible experiments. The lack of rigorous quantitative approaches in current western blot statistical methodology may result in irreproducible inferences. Here we describe best practices for the design and analysis of western blot experiments, with examples and demonstrations of how different analytical approaches can lead to widely varying outcomes. To facilitate best practices, we have developed the blotRig tool for designing and analyzing western blot experiments to improve their rigor and reproducibility. The blotRig application includes functions for counterbalancing experimental design by lane position, batch management across gels, and analytics with covariates and random effects.

pJoseph2: a family of plasmids as positive controls for bacterial protein expression, transfections, and western blots.

Epitope tagging represents a powerful strategy for expedited identification, isolation, and characterization of proteins in molecular biological studies, including protein-protein interactions. We aimed to improve the reproducibility of epitope-tagged protein expression and detection by developing a range of plasmids as positive controls. The pJoseph2 family of expression plasmids functions in diverse cellular environments and cell types to enable the evaluation of transfection efficiency and antibody staining for epitope detection. The expressed green fluorescent proteins harbor five unique epitope tags, and their efficient expression in Escherichia coli, Drosophila Schneider's line 2 cells, and human SKOV3 and HEK293T cells was demonstrated by fluorescence microscopy and western blotting. The pJoseph2 plasmids provide versatile and valuable positive controls for numerous experimental applications.

Epitope tagging, a fundamental technique in molecular biology, involves attaching short amino acid sequences (epitope tags) to target proteins for their efficient identification and study. This technique has evolved since its inception, enabling diverse applications in protein research. Notably, CRISPR/Cas9 gene editing has enhanced epitope tagging by enabling the tagging of endogenous genes, expanding its versatility. However, reproducibility challenges exist, demanding positive controls for troubleshooting. The pJoseph2 family of plasmids was developed to address this need, providing robust positive controls for various epitope-based experiments, from bacterial expression to Drosophila and mammalian cell studies. This resource enhances the reliability and accuracy of epitope tagging, benefiting researchers across disciplines.

A guide to selecting high-performing antibodies for Synaptotagmin-1 (Uniprot ID P21579) for use in western blot, immunoprecipitation, immunofluorescence and flow cytometry.

Synaptotagmin-1 is a synaptic vesicle transmembrane protein that senses calcium influx via its tandem C2-domains, triggering synchronous neurotransmitter release. Disruption to SYT1 is associated with neurodevelopmental disorders, highlighting the importance of identifying high-quality research reagents to enhance understanding of Synaptotagmin-1 in health and disease. Here we have characterized thirteen Synaptotagmin-1 commercial antibodies for western blot, immunoprecipitation, immunofluorescence and flow cytometry using a standardized experimental protocol based on comparing read-outs in knockout cell lines and isogenic parental controls. These studies are part of a larger, collaborative initiative seeking to address antibody reproducibility issues by characterizing commercially available antibodies for human proteins and publishing the results openly as a resource for the scientific community. While use of antibodies and protocols vary between laboratories, we encourage readers to use this report as a guide to select the most appropriate antibodies for their specific needs.

Detection of Antibodies against Feline Morbillivirus by Recombinant Matrix Enzyme-Linked Immunosorbent Assay.

Feline morbillivirus (FeMV) has been associated with feline health, although its exact role in pathogenesis is still debated. In this study, an indirect enzyme-linked immunosorbent assay (i-ELISA) targeting a recombinant matrix protein of FeMV (rFeMV-M) was developed and assessed in comparison to a Western blotting (WB) assay. The i-ELISA was evaluated using blood samples from 136 cats that were additionally tested with real-time reverse-transcription PCR (RT-qPCR). The i-ELISA exhibited a sensitivity of 90.1%, specificity of 75.6%, positive predictive value of 88.2%, and negative predictive value of 79.1%. The agreement between i-ELISA and WB analyses was substantial (a κ coefficient of 0.664 with a 95% confidence interval of 0.529 to 0.799). Within the study group, 68.4% (93/136) of the cats were serologically positive in the i-ELISA and 66.9% (91/136) in the WB assay, with 11.8% (11/93) of false positivity with the i-ELISA. However, only 8.1% (11/136) of the cats tested positive for FeMV using RT-qPCR (p < 0.001). The developed i-ELISA proved effective in identifying FeMV-infected cats and indicated the prevalence of FeMV exposure. Combining FeMV antibody detection through i-ELISA with FeMV RT-qPCR could offer a comprehensive method to determine and monitor FeMV infection status. Nevertheless, this assay still requires refinement due to a significant number of false positive results, which can lead to the misdiagnosis of cats without antibodies as having antibodies. This study also provided the first evidence of seroprevalence against FeMV among cat populations in Thailand, contributing valuable insights into the geographic distribution and prevalence of this virus.

Senescence detection using reflected light.

Senescence is an important cellular program occurring in development, tissue repair, cancer, and aging. Increased senescence is also associated with disease states, including obesity and Type 2 diabetes (T2D). Characterizing and quantifying senescent cells at a single cell level has been challenging and particularly difficult in large primary cells, such as human adipocytes. In this study, we present a novel approach that utilizes reflected light for accurate senescence-associated beta-galactosidase (SABG) staining measurements, which can be integrated with immunofluorescence and is compatible with primary mature adipocytes from both human and mouse, as well as with differentiated 3T3-L1 cells. This technique provides a more comprehensive classification of a cell's senescent state by incorporating multiple criteria, including robust sample-specific pH controls. By leveraging the precision of confocal microscopy to detect X-gal crystals using reflected light, we achieved superior sensitivity over traditional brightfield techniques. This strategy allows for the capture of all X-gal precipitates in SABG-stained samples, revealing diverse X-gal staining patterns and improved detection sensitivity. Additionally, we demonstrate that reflected light outperforms western blot analysis for the detection and quantification of senescence in mature human adipocytes, as it offers a more accurate representation of SABG activity. This detection strategy enables a more thorough investigation of senescent cell characteristics and specifically a deeper look at the relationship between adipocyte senescence and obesity associated disorders, such as T2D.

Expression of F1L, a vaccinia virus H3L transmembrane protein analogue of orf virus, and its successful purification as a diagnostic antigen.

Orf or contagious ecthyma is a highly contagious, zoonotic, and economically important global viral disease of small ruminants and is endemic in India. Vaccination of susceptible goats/sheep along with suitable recombinant protein-based serological assay will be useful in the control of the infection. In this study, the full-length and truncated versions of F1L encoding gene (ORF 059) of orf virus were cloned into pFasBac HT A vector, transformed in DH10Bac cells, and expressed in insect cells. The full-length and truncated recombinant F1L proteins were expressed as a 6 × histidine-tagged fusion protein for ease of purification by Ni-NTA affinity chromatography under denaturing conditions. A protein with ~ 40 kDa and ~ 35 kDa for full-length and truncated F1L protein, respectively, were expressed and confirmed by SDS-PAGE and western blot. The protein reactivity evaluated by western blot analysis and indirect ELISA using ORFV hyperimmune serum was also found to be reactive. The results of the present study showed that the purified recombinant F1L protein can be used as a diagnostic antigen in sero-surveillance of ORFV infection in small ruminants. To the best of authors' knowledge, this is the first report on the expression of ORFV F1L in insect cells using a baculovirus vector and its successful purification to use as the potential diagnostic antigen in ELISA.