Molecular sentinel

Fig. 13.7 The operating principle of the SERS-based molecular sentinel (MS) nanoprobes, (a) The MS nanoprobe is composed of a Raman-labeled DNA hairpin probe and a silver nanoparticle. In the absence of the complementary target DNA, a strong SERS signal is observed due to the hairpin conformation adopted by the MS nanoprobe (left closed state), (b) In the presence of the complementary target DNA, the hairpin conformation of the MS nanoprobe is disrupted and the SERS signal is quenched due to the physical separation of the Raman label from the surface of the silver...

Wang H-N, Vo-Dinh T (2009) Multiplex detection of breast cancer biomarkers using plasmonic molecular sentinel nanoprobes. Nanotechnology 20 065101 (6 pp)... 

Fig. 7.2 Signalling concept of SERS molecular sentinels (MS). Strong SERS signal is observed when the MS nanoprobe is in the hairpin closed conformation (which is in the absence of target DNA). SERS signal is diminished in the presence of the target DNA which causes opening of MS (adapted with permission from Wabuyele et al. 2010. Copyright 2010 Springer)...

W. Pang, J. Wang, R. Xiao, S. Wang, SERS molecular sentinel for the RNA genetic marker of PB1-F2 protein in highly pathogenic avian influenza (HPAI) virus. Biosens. Bioelectron. 61, 460 (2014)... 

Surface-enhanced Raman scattering molecular sentinel nanoprobes for viral infection diagnostics. Anal. Chim. Acta 786, 153 (2013a)... 

Wirgin, I.I. and Garte, S. (1994) Assessment of environmental degradation by molecular analysis of a sentinel species Atlantic tomcod. In Molecular Environmental Biology, Garte S.J. (ed.), pp. 117—132. Lewis Publishers, Boca Raton, FL. 

Intra-operative Molecular Testing of Sentinel Lymph Node... 

Hughes SJ, Xi L, Raja S, et al. A rapid, fully automated, molecular-based assay accurately analyzes sentinel lymph nodes for the presence of metastatic breast cancer. Ann Surg. 2006 243 389-398. 

Martin Martinez MD, Veys I, Majjaj S, et al. Glinical validation of a molecular assay for intra-operative detection of metastases in breast sentinel lymph nodes. Eur J Surg Oncol. 2009 35 387-392. 

Lymph node staging and mapping of lymphatic routes by examination of the sentinel lymph nodes using a RT-PCR-based method found to be a better predictor of possible recurrence of various tumors and fundamental for the success of the therapy. Molecular screening of sentinel lymph nodes is now frequently used for the staging of some tumors like melanoma and breast cancer. 

Despite the high sensitivity and specificity of PCR-based molecular methods, falsepositive and false-negative results are reported. Source for false-positive results can be the contamination by skin melanocytes during blood or bone marrow collection or the temporary circulation of skin melanocytes after surgical intervention or due to the presence of nodal melanocytic nevi, when regional or sentinel lymph nodes are examined. 

Abdul-Rasool, S. Kidson, S. H. Panieii, E. Dent, D. Pillay, K. Hanekom, G. S. An evalnation of molecular markers for improved detection of breast cancer metastases in sentinel nodes. J. Clin. Pathol. 2006, 59, 289-297. 

Many hospital and private reference laboratories use what are called the rule-out-and-refer (ROAR) guidelines as defined and made available by the CDC. The laboratories that use these procedures are referred to as sentinel laboratories in the CDC s Laboratory Response Network (LRN) (Centers for Disease Control and Prevention 2014). The guidelines are utilized to rule out the presence of biological agents with the use of just a few rapid method biochemical reactions. If the organism cannot be ruled out, the sentinel laboratory s role is not to identify the organism but rather is required to refer to the state s public health laboratory, where confirmation can be achieved by advanced biochemical tests, gene amplification, and other molecular methods. 

Heat resistance test at 100 °C - Sentinel heat seal tester Set-up a Sentinel heat sealer according to heat pressure and time interval specified. A one by three inch (2.5 cm X 7.5 cm) print sample is folded ink surface-to-ink surface and placed between the sealer bars. The heat sealer is operated. After the sample has been cooled, the sheets are separated and a subjective comparison is made for cling, ink transfer and picking. The jxjlymer glass transition temperature (Tg), molecular weight, and surface compatibility affect heat resistance. 

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