CHAPTER I INTRODUCTION The use of amniotic fluid to assess the ...

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already be near to senescence. This research effort isolates cells by cloning for
homogeneity to retrieves the more unique and stable continuous amniotic cell lines.
When a new cell line has derived, it is necessary to evaluate details of its origin
and expressed features. This aspect of cell culture is a crucial important with the
widespread dissemination of a cell line through research laboratories and cell banks. In
particular if a cell line becomes incorporated into a research that requires validation of
its components, then the authentications of the cell line get necessary. It is, therefore,
vital that detailing the origin and handling of the cell lines are kept from the time of
isolation and periodically during use. The purpose of a cell line to be characterized are
depending on the situation of use such as; to confirm the species of origin, to correlate
with the tissue origin, to determine the cell line transformation, to demonstrate the
cross-contamination, to indicate the prone of genetic instability and phenotypic
variation, and to identify a specific cell line with in a group from the same origin
(Butler and Dowson, 1992; Freshney, 2000). Several detailed protocols to success of
the above purpose are widely available (Kuchler, 1977; Masters, 2000; Freshney,
2000). However, some basic characteristics are studied in this research for the newly
form cell lines and their sub-clones including; morphology (type of cells in cultures),
plating efficiency (the percentage of cells seeded at subculture that gives rise to
colony), seeding efficiency (the percentage of the inoculums that attaches to the
substrate within a stated period of time), growth pattern or growth curve (a
semilogarithmic plot of the cell number on a logarithmic scale against time on a linear
scale for a proliferating cell culture), viability (survival of the cells) and the
karyotyping (the distinctive chromosomal complement of cells). These characteristics
will be very useful for any future research with the continuous cell lines.
Amniotic cells containing many of cell types present in the original tissue.
A wide variety of investigations performed since the 1980s have provided evidences
that cells of all three germ layers (ectoderm, mesoderm and endoderm) can be
detected in human amniotic fluid (Hoenh and Salk, 1982 and Gosden, 1983). Despite,
the widespread and well-established use of amniotic cells in routine prenatal genetic
testing, current knowledge about the origin and properties of these cells is
limited (Prusa and Hengstschläger, 2002). Recently, some reports mentioned that the
amniotic fluid contained a variety of stem cells, which were shed from embryonic and