Abstract: Methods for classifying neuroendocrine neoplasms (NENs) are based on comprehensive microRNA (miRNA) expression profiling and data mining of multiple pathological types. Reference miRNA expression profiles are generated for multiple NEN pathological types and site-matched non-NEN controls, and candidate category and type specific miRNAs are identified and used for 5 classification. A multilayer hierarchical classifier for discriminating NEN pathological types is based on the candidate category and type specific miRNAs. Methods and software products include products that enable construction of discriminator functions including hierarchical classifiers for discriminating among multiple conditions of interest in a dataset, the methods and software products being applicable to a wide range of data modalities, including, for example, omits data 0 such as miRNA expression data wherein multiple conditions of interest include different cancer pathologies.

Abstract: The invention provides a method for fixing an RNA molecule in a biological sample. The method comprises contacting the biological sample with an aldehyde-containing fixative, and subsequently contacting the sample with a solution comprising a carbodiimide and a heterocyclic derivative selected from the group consisting of an imidazole, pyrazole, triazole or tetrazole or a combination thereof. A method for differentiating cells in a biological sample is also provided. A method for quantification of RNA retention in a biological sample is also provided. A kit for fixing RNA in a sample is provided as well.

Abstract: The invention provides a method for fixing an RNA molecule in a biological sample. The method comprises contacting the biological sample with an aldehyde-containing fixative, and subsequently contacting the sample with a solution comprising a carbodiimide and a heterocyclic derivative selected from the group consisting of an imidazole, pyrazole, triazole or tetrazole or a combination thereof. A method for differentiating cells in a biological sample is also provided. A method for quantification of RNA retention in a biological sample is also provided. A kit for fixing RNA in a sample is provided as well.