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R N Mukherjee

Publications and source records attributed to R N Mukherjee.

5 recordsLinked to original sources
PubMed1992

Silanized silica bound trypsin as analytical probe.

Trypsin immobilized by covalent coupling to silanized silica shows significant activity (30-38%) and greater thermostability as compared to soluble trypsin. Proteolytic processing of albumin at varying periods suggest that the enzyme matrix can be used efficiently for limited proteolysis. Repeated use of the immobilized enzyme in protein digestion produces similar products as seen by electrophoretic analysis. Also, digestion of albumin by the immobilized enzyme follows similar pattern as that by soluble enzyme. The enzyme matrix can be easily removed from the incubation mixture. The results indicate the possibility of the immobilized enzyme for its effective application as analytical tool in peptide mapping and limited proteolytic processing.

Electrophoresis, Polyacrylamide Gel↗
PubMed1982

Evaluation of radiation-induced chromosomal aberrations in human peripheral blood lymphocytes in vitro: result of an IAEA-coordinated programme.

The results of an IAEA coordinated programme on radiation induced chromosomal aberrations in human peripheral blood lymphocytes in vitro are presented. In a master experiment, a whole blood sample from one donor was irradiated with 200 R of X-rays. Different fixation times from 46 to 82 h were used. The progression of cells into mitosis was monitored by BrdUrd incorporation. 14 investigators took part in the scoring of chromosomal aberrations. The main conclusions of this study are: (1) The mean frequencies of aberrations changed with fixation time. (2) The number of cells scored as aberrant by different laboratories was very similar, but there was variability in the number of aberrations scored per aberrant cell. (3) The differences in the frequencies of aberrations between laboratories were minimal when the scoring was restricted to the first major peak of mitotic activity and sufficient cells were scored. It is concluded that using controlled experimentals conditions, human peripheral blood lymphocytes can effectively be used as a reliable biological dosimeter for absorbed radiation dose.

Argentina↗
PubMedDate not supplied

Effect of low-dose acute X-irradiation on the frequencies of chromosomal aberrations in human peripheral lymphocytes in vitro.

In a coordinated research programme sponsored by the International Atomic Energy Agency, the frequencies of chromosomal aberrations induced in peripheral blood lymphocytes (in vitro) by 250 kV X-rays at low doses (0.4, 1, 2, 3, 5, 10 and 30 rad) were determined. Blood from 2 donors was used to conduct one master experiment at these dose levels. The culture time used was 48 h and all samples including the controls were processed according to a standard protocol. The coded slides were scored by investigators from 10 participating laboratories. The main results are the following: (1) the frequencies of all types of chromosome aberrations at 0.4 rad are significantly lower than the control values; (2) there is no increase in the frequencies of dicentrics up to 2 rad and in those of terminal deletions up to 5 rad; (3) the mean frequencies of all aberrations considered together are not significantly different from one another at 1, 2 and 3 rad (P = 0.05); and (4) over the entire dose range the dose-effect relationship is clearly non-linear. A fit of these data to a linear quadratic model (E(D) = c + alpha D + beta D2) showed that the observed total aberration frequencies at doses 1, 2, 3 and 5 rad are below the curve defined by the model. The deviations can be explained by an altered kinetics of aberration production at very low doses probably due to DNA repair mechanisms operating these cells.

Adult↗