Development of highly reliable SERS‐active photonic crystal fiber probe and its application in the detection of ovarian cancer biomarker in cyst fluid

Conventionally Surface‐enhanced Raman spectroscopy (SERS) is realized by adsorbing analytes onto nano‐roughened planar substrate coated with noble metals (silver or gold) or their colloidal nanoparticles (NPs). Nanoscale irregularities in such substrates/NPs could lead to SERS sensors with poor reproducibility and repeatability. Herein, we demonstrate a suspended core photonic crystal fiber (PCF) based SERS sensor with extremely high reproducibility and repeatability in measurement with a relative SD of only 1.5% and 4.6%, respectively, which makes it more reliable than any existing SERS sensor platforms. In addition, our platform could improve the detection sensitivity owing to the increased interaction area between the guided light and the analyte, which is incorporated into the holes that runs along the length of the PCF. Numerical calculation established the significance of the interplay between light coupling efficiency and evanescent field distribution, which could eventually determine the sensitivity and reliability of the developed SERS active‐PCF sensor. As a proof of concept, using this sensor, we demonstrated the detection of haptoglobin, a biomarker for ovarian cancer, contained within the ovarian cyst fluid, which facilitated in differentiating the stages of cancer. We envision that with necessary refinements, this platform could potentially be translated as a next‐generation highly sensitive SERS‐active opto‐fluidic biopsy needle for the detection of biomarkers in body fluids.     

Production and characterisation of monoclonal antibodies to an Indian isolate of peste des petits ruminants virus

Nine monoclonal antibodies (Mabs) were produced against an Indian isolate of peste des petits ruminants (PPR) virus. These Mabs were directed against the nucleo (N) protein and were of IgG1 isotype. The Mabs produced intranuclear or coarse granular cytoplasmic fluorescence in PPR virus infected Vero cells and did not exhibit any neutralising activity. The Mabs cross-reacted with five other local isolates of PPR virus in slot blot hybridisation, radio immunoprecipitation assay (RIPA) and fixed-cell enzyme linked immunosorbent assay (ELISA). Two of the nine Mabs cross-reacted mildly with the vaccine strain of rinderpest (RP) virus in slot blot hybridisation and fixed-cell ELISA but did not precipitate the N protein of RP virus in RIPA. The N protein specific Mabs will be highly useful in differential diagnosis of PPR from RP.     

Use of Simple Sequence Repeat Markers for Estimation of Genetic Diversity in Coconut (Cocos nucifera L) Germplasm Accessions

Simple Sequence Repeat (SSR) markers were used to determine the genetic relationship among 33 coconut germplasm accessions collected from different geographical regions. Wide range of Jaccard’s similarity coefficient (0.00–0.86) reflects the informativeness of the SSR markers. Dwarf and intermediate accessions showed highest similarity among them. The tall accessions belonging to South East Asia, South Asia and South Pacific were clustered based on their geographical regions, but dwarf and intermediate accessions were clustered separately. Clustering of accessions belonging to Atlantic and America revealed the spread of coconut from Far East to South Pacific. Principal coordinate plot and UPGMA analyses formed similar groups of the accessions.     

Role of large hydrophobic residues in proteins

Large Hydrophobic Residues (LHR) such as phenylalanine, isoleucine, leucine, methionine and valine play an important role in protein structure and activity. We describe the role of LHR in complete set of protein sequences in 15 different species. That is the distribution of LHR in different proteins of different species is reported. It is observed that the proteins prefer to have 27% of large hydrophobic residues in total and all along the sequence. It is also observed that proteins accumulate more LHR in its active sites. A window analysis on these protein sequences shows that the 27% of LHR is more frequent at window length of 45 amino acids. The influenza virus and P. falciparum show a random distribution of LHR in its proteins compared to other model organisms.     

A mouse c-ros genomic clone: identification of a highly conserved 22-amino acid segment in the juxta-membrane domain.

The mouse c-ros protooncogene genomic sequences have been cloned; an analysis of the partial genomic clone revealed a high conservation of the exons encoding the juxta-membrane (JM) and the 5' most protein tyrosine kinase domains. We have identified a segment of 22 amino acids conserved between the human and mouse JM domains; this segment may have a critical role in the function of the c-ros-encoded protein tyrosine kinase receptor.