Cell culture assays

Cell culture assays

In Biomaterials Testing, a cell culture assay is any method which is used to assess the cytotoxicity of a material. This refers to the "in vitro" assessment of material to determine whether it releases toxic chemicals in sufficient quantities to kill cells either directly or indirectly through the inhibition of cell metabolic pathways. Cell culture evaluations are the precursor to whole animal studies and are a way to determine if significant cytotoxicity exists for the given material. Cell culture assays are standardized by ASTM, ISO, and BSI (British Standards Institution.)


Direct contact method

# A near confluent layer of fibroblasts are prepared in a culture plate
# Old cell culture media (agar generally) is removed
# Fresh media is added
# Material being tested is placed onto the cultures, which are incubated for 24 hours at 37 degrees Celsius
# The material is removed
# The culture media is removed
# The remaining cells are fixed and stained, dead cells are lost during fixation and only the live cells are stained
# The toxicity of the material is indicated by the absence of stained cells around the material

Agar diffusion method

# A near confluent layer of fibroblasts are prepared in a culture plate
# Old cell culture media is removed
# The cells are covered with a solution of 2% agar, which often contains red vital stain
# When the agar solidifies the cells will have dispersed throughout its volume
# The material is then placed on the surface of the agar and incubated for 24 hours at 37 degrees Celsius
# Live cells take up the vital stain and retain it, dead cells do not
# The toxicity of the material is evaluated by the loss of vital stain under and around the material
# Surface microscopy is also needed to evaluate the material-cell interfacae

Elution method

# A near confluent layer of fibroblasts are prepared in a culture plate
# An extract of the material which is being tested is prepared using physiological saline or serum free media (the latter is generally preferred)
# Extraction conditions are used which are appropriate for the type of exposure which the cells would receive in the "in vivo" environment if the material were to be implanted
# The extract is placed on the cells and incubated for 48 hours at 37 degrees Celsius
# After 48 hours the toxicity is evaluated using either a histochemical or vital stain

Each method has its own advantages and disadvantages, and some are more suitable for certain applications than others. For example the direct contact method offers conditions which are most similar to the physiological environment but the cells are suceptible to trauma if the material moves. The agar diffusion method is good for materials with high densities and offers an even concentration gradient for potential toxicants, but there is a serious risk of the cells going into thermal shock when they are overlayed with agar. The elution method is best for applications which might require extra incubation time, but additional time and steps are required for preparing such a test.

"In vitro" biomaterials testing yields fundamental information about the behavior of materials in contact with living cells, but cannot qualify or even accurately predict the performance of a material "in vivo".

Wikimedia Foundation. 2010.

Поможем написать курсовую

Look at other dictionaries:

  • Cell culture — in a Petri dish Epithelial cells in culture, stained for keratin (red) an …   Wikipedia

  • cell culture — ▪ biology       the maintenance and growth of the cells of multicellular organisms outside the body in specially designed containers and under precise conditions of temperature, humidity, nutrition, and freedom from contamination. In a broad… …   Universalium

  • cell — cell1 cell like, adj. /sel/, n. 1. a small room, as in a convent or prison. 2. any of various small compartments or bounded areas forming part of a whole. 3. a small group acting as a unit within a larger organization: a local cell of the… …   Universalium

  • Hematopoietic stem cell — HSC=Hematopoietic stem cell, Progenitor=Progenitor cell, L blast=Lymphoblast, Lymphocyte, Mo blast=Monoblast, Monocyte, Myeloblast …   Wikipedia

  • Stem cell — Mouse embryonic st …   Wikipedia

  • American Type Culture Collection — The American Type Culture Collection (ATCC) is a private, not for profit biological resource center whose mission focuses on the acquisition, authentication, production, preservation, development and distribution of standard reference… …   Wikipedia

  • Malaria culture — P. falciparum cultures[1] Malaria culture is the method to grow malaria parasites outside the body i.e. in an ex vivo environment. Plasmodium falciparum is currently the only human malaria paras …   Wikipedia

  • Episodic ataxia — (EA) is an autosomal dominant disorder characterized by sporadic bouts of ataxia (severe discoordination) with or without myokymia (continuous muscle movement). Ataxia can be provoked by stress, startle, or heavy exertion such as exercise.… …   Wikipedia

  • Chemically defined medium — A chemically defined medium is a growth medium suitable for the in vitro cell culture of human or animal cells in which all of the chemical components are known. The term chemically defined medium was defined by Jayme and Smith (2000) as a Basal… …   Wikipedia

  • PKN3 — is a protein kinase C related molecule and thought to be an effector mediating malignant cell growth downstream of activated phosphoinositide 3 kinase (PI3K). It is thought that chronic activation of the phosphoinositide 3 kinase (PI3K)/PTEN… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”