Dr. Ashfaq A . Khan
Professor of Chemistry (Retired). Did Ph. D. work from Max-Rubner Institute, Karlsruhe, Germany. Published about 16 papers in National, International, European and American Research Journals. Major fields of research are Detection of irradiated Foods, Investigation of ill effects of pesticides, herbicides, insecticides, fungicides, nano-particles and heavy metals on aquatic life (Fish), Removal of hazardous substances from water, Evaluation of Anti-oxidant potential of different foods. Presented Research work in several National and International Conferences. Teaching of Chemistry at Master and BS levels. Research Supervisor of BS chemistry students. About 34 years of teaching experience of chemistry.
Phone: +92-3315857180
Address: Dr. Ashfaq Ahmad Khan, Village: Gehr Khan, P.O: Sarai Saleh, Haripur, KP, Pakistan.
Phone: +92-3315857180
Address: Dr. Ashfaq Ahmad Khan, Village: Gehr Khan, P.O: Sarai Saleh, Haripur, KP, Pakistan.
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Papers by Dr. Ashfaq A . Khan
radiation treatment of several kinds of leguminous beans (azuki, black, black eye, mung, pinto, red kidney and white
beans). Each variety was exposed to radiation doses of 0.5, 1 and 5 kGy covering the permissible limits for insect
disinfestation. The cells or nuclei from beans were extracted in cold PBS, embedded in agarose on microscope slides,
lysed between 15 and 60 min in 2.5% SDS and electrophoresis was carried out at a voltage of 2 V/cm for 2–2.5 min.
After silver staining, the slides were evaluated through an ordinary transmission microscope. In irradiated samples,
fragmented DNA stretched towards the anode and the damaged cells appeared as a comet. The density of DNA in the
tails increased with increasing radiation dose. However, in non-irradiated samples, the large molecules of DNA
remained relatively intact and there was only minor or no migration of DNA; the cells were round or had very short
tails only. Hence, the DNA comet assay provides an inexpensive, rapid and relatively simple screening method for the
detection of irradiated beans. r 2002 Elsevier Science Ltd. All rights reserved.
Keywords: Beans; Irradiation; Detection of irradiated food; DNA comet assay
lentils, yellow lentils, chickpeas, green peas, cowpeas and
yellow peas) and grams (black grams, red grams and white
grams) have been investigated for the identification of
radiation treatment using microgel electrophoresis of single
cells (DNA comet assay). Pulses and grams were exposed
to the radiation doses of 0.5, 1.0 and 5 kGy covering the
legalized commercial dose range for protection from insect/
pest infestations. All irradiated samples showed comet like
stretching of fragmented DNA toward anode, which is
expected for irradiated samples. Unirradiated samples
showed many intact cells/nuclei in form of round stains or
with short faint tails, which is typical for unirradiated food
samples. The study shows that DNA comet assay can be
used as a rapid, inexpensive and highly effective screening
test for the detection of radiation treatment of foods, like
pulses and grams
radiation treatment of several kinds of leguminous beans (azuki, black, black eye, mung, pinto, red kidney and white
beans). Each variety was exposed to radiation doses of 0.5, 1 and 5 kGy covering the permissible limits for insect
disinfestation. The cells or nuclei from beans were extracted in cold PBS, embedded in agarose on microscope slides,
lysed between 15 and 60 min in 2.5% SDS and electrophoresis was carried out at a voltage of 2 V/cm for 2–2.5 min.
After silver staining, the slides were evaluated through an ordinary transmission microscope. In irradiated samples,
fragmented DNA stretched towards the anode and the damaged cells appeared as a comet. The density of DNA in the
tails increased with increasing radiation dose. However, in non-irradiated samples, the large molecules of DNA
remained relatively intact and there was only minor or no migration of DNA; the cells were round or had very short
tails only. Hence, the DNA comet assay provides an inexpensive, rapid and relatively simple screening method for the
detection of irradiated beans. r 2002 Elsevier Science Ltd. All rights reserved.
Keywords: Beans; Irradiation; Detection of irradiated food; DNA comet assay
lentils, yellow lentils, chickpeas, green peas, cowpeas and
yellow peas) and grams (black grams, red grams and white
grams) have been investigated for the identification of
radiation treatment using microgel electrophoresis of single
cells (DNA comet assay). Pulses and grams were exposed
to the radiation doses of 0.5, 1.0 and 5 kGy covering the
legalized commercial dose range for protection from insect/
pest infestations. All irradiated samples showed comet like
stretching of fragmented DNA toward anode, which is
expected for irradiated samples. Unirradiated samples
showed many intact cells/nuclei in form of round stains or
with short faint tails, which is typical for unirradiated food
samples. The study shows that DNA comet assay can be
used as a rapid, inexpensive and highly effective screening
test for the detection of radiation treatment of foods, like
pulses and grams