Abstract: Methods and compositions are provided for modulating, e.g., increasing or decreasing, the expression of telomerase reverse transcriptase (TERT). In the subject methods, the binding interaction of the TERT Site C repressor site with a Site C repressor protein complex made up of one or more proteins is modulated to achieve the desired change in TERT expression. A feature of the subject invention is that the target Site C repressor protein complex includes an LSF protein. The subject methods and compositions find use in a variety of different applications, including the immortalization of cells, the production of reagents for use in life science research, therapeutic applications; therapeutic agent screening applications; and the like.

Abstract: The present invention provides a simple and efficient method of preparing an analyte-enzyme conjugate where the enzyme contains free, surface-accessible carboxyl moieties without generating undesired, cross-linked enzymes, while preserving CN the functionality of the enzyme. The method involves treating an enzyme with a blocking agent such that the free carboxyl moieties become non-reactive prior to the conjugation reaction with the desired analyte. The yield of the analyte-enzyme conjugate and the purity of the conjugates formed are high since cross-linking of the blocked enzymes is minimized or prevented. The invention is generally useful in preparing any conjugates of an analyte of interest and an enzyme containing surface accessible carboxyl moieties. The invention is particularly useful in preparing conjugates of any analyte of interest and horseradish peroxidase, alkaline phos-phatase or acetylcholine esterase.