Cataclysmic Variables from USNO-B1.0 Catalog: Stars with Outbursts on Infrared Palomar Plates

The search was performed for cataclysmic variable stars with outlying infrared magnitudes in USNO-B1.0 catalog. The selection was limited to objects in the Northern hemisphere with (B1-R1) 3.5. The search method is described, and the details on individual stars are given. In total 27 variable objects were found with 20 being the previously known ones and 7 - new discoveries. 4 of newly found variables are dwarf novae, while the remaining 3 - pulsating red variables of Mira or semi-regular types, including a heavily reddened one in Pelican nebula. The correct pulsation period is determined for two stars discovered by other researchers, and the dwarf nova nature is confirmed for another object previously suspected as such. The perspectives of the proposed search technique in the framework of Virtual Observatory are also discussed.Comment: 8 pages, 10 figures, submitted to Astronomy Letter

Identification of new cataclysmic variables in the 1RXS and USNO-B1.0 catalogs

As a result of applying the original optical variability search method on publicly available data, we have found eight new cataclysmic variables and two possible Optically Violent Variable quasars among the previously unidentified X-ray sources in the ROSAT catalog. We describe the search method and present the characteristics of the newly identified variable stars. The obtained results demonstrate the large potential of the concept of Virtual Observatory for identifying new objects of astrophysical interest.Comment: 16 pages, 11 figures, 2 tables; submitted to Astronomy Letter

New Cataclysmic Variable 1RXS J073346.0+261933 in Gemini

In course of the search for the optical identifications associated with ROSAT X-ray sources we have found a highly variable object with the very unusual long-term behavior, color indices and high X-ray-to-optical flux ratio. We report the archival photometric light curve from the Catalina Sky Survey, optical spectroscopy from RTT150 and time-resolved photometry from Astrotel-Caucasus telescope. The object appears to be the magnetic cataclysmic variable (polar) with orbital period of P=3.20 hr.Comment: 8 pages, 5 figures. Submitted to Astronomy Letter

Fast chromatin immunoprecipitation assay

Chromatin immunoprecipitation (ChIP) is a widely used method to explore in vivo interactions between proteins and DNA. The ChIP assay takes several days to complete, involves several tube transfers and uses either phenol–chlorophorm or spin columns to purify DNA. The traditional ChIP method becomes a challenge when handling multiple samples. We have developed an efficient and rapid Chelex resin-based ChIP procedure that dramatically reduces time of the assay and uses only a single tube to isolate PCR-ready DNA. This method greatly facilitates the probing of chromatin changes over many time points with several antibodies in one experiment