A simple histological technique to improve immunostaining when using DNA denaturation for BrdU labelling

Although, as is well known, the ultra-microscopic viruses are invisible in histological preparations, yet characteristic bodies occur within certain of the cells of animals infected with such organisms. The origin and nature of these so-called “virus bodies” has been the subject of much controversy. By some they have been regarded as the actual parasite, or at least as phases in its life cycle. To von Prowazek they were dual in character consisting of microorganisms embedded in material produced by the reaction of the cytoplasm of the infected cell. Still other observers regarded such bodies as products of cellular disintegration. In a former paper (Findlay and Ludford (1926)) we have referred to the various views held by writers in this field and have made a survey of the literature of the subject in the form of a pictographic review. We shall, therefore, only mention previous work in this field, in so far as it directly concerns our personal observations. A conspicuous fault of much of the earlier work has been the unsatisfactory histological technique employed, especially the nature of the fixative. The earlier cytological work was carried out with fixatives, which although satisfactory for the subsequent demonstration of nuclear structures were very destructive to the cytoplasm. This is particularly unfortunate since most of the virus bodies occur in the ground cytoplasm of cells. We have endeavoured to rectify this source of error in our work by employing fixatives, which have been proved to fix the cells in such a manner as to give an appearance as nearly as possible identical with their structure, as seen in the living cells.

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Investigation of DNA denaturation from generalized Morse potential

OAJ Materials and Devices ◽

10.23647/ca.md20180207 ◽

2018 ◽

Vol 3 (2) ◽

Author(s):

R. El Kinani ◽

H. Kaidi ◽

M. Benhamou

Keyword(s):

Morse Potential ◽

Bound States ◽

Analytical Study ◽

Free Energy Density ◽

Exact Expression ◽

Dna Denaturation ◽

Denaturation Temperature ◽

Finite Distance ◽

The Mean ◽

Generalized Morse Potential

In this paper, we present a non-linear model for the study of DNA denaturation transition. To this end, we assume that the double-strands DNA interact via a realistic generalized Morse potential that reproduces well the features of the real interaction. Using the Transfer Matrix Method, based on the resolution of a Schrödinger equation, we first determine exactly their solution, which are found to be bound states. Second, from an exact expression of the ground state, we compute the denaturation temperature and the free energy density, in terms of the parameters of the potential.Then, we calculate the contact probability, which is the probability to find the double-strands at a (finite) distance apart, from which we determine the behaviour of the mean-distance between DNA-strands.The main conclusion is that, the present analytical study reveals that the generalized Morse potential is a good candidate for the study of DNA denaturation

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