File Name: advantages and disadvantages of primary and secondary cells .zip
A primary cell is a battery a galvanic cell that is designed to be used once and discarded, and not recharged with electricity and reused like a secondary cell rechargeable battery.
Primary cells most closely represent the tissue of origin. They are taken directly from the tissue and processed to establish them under optimized culture conditions. Because they are derived from tissue and not modified, they are more similar to the in vivo state and exhibit normal physiology. For this reason, they provide excellent model systems for studying the normal physiology and biochemistry of cells e. Keep in mind that primary cells have a limited lifespan and will stop dividing or senesce after a certain number of cell divisions and can be more difficult to culture and maintain than a continuous cell line.
The variability induced in primary cells acquired from donors and during subculture practices is a major challenge faced by the researchers who study cell signaling pathways. Researchers prefer to screen the cells for sensitivity to common stimuli before embarking on signaling studies. Pre-screened primary cells save valuable resources as they are stimulated for activation of major signaling pathways.
The most popular types of primary cells used in research are epithelial cells, fibroblasts, keratinocytes, melanocytes, endothelial cells, muscle cells, hematopoietic and mesenchymal stem cells. The cultures are initially heterogeneous represents a mixture of cell types present in the tissue and can be maintained in vitro only for a limited period of time.
Primary cells may be manipulated for indefinite subculture through an in vitro process called transformation. Transformation can occur spontaneously or can be chemically or virally induced.
When a primary culture undergoes genetic transformation provided with appropriate fresh medium and space , they divide indefinitely and become an immortalized secondary cell line. Continuous cell lines have acquired the ability to proliferate indefinitely immortalized either through random mutation as in transformed cancer cell lines , or by deliberate modification such as artificial expression of cancer genes.
Continuous cell lines are generally more robust and easier to work with than primary cells. They have unlimited growth potential and are a quick, easy way to get basic information.
It is also used in drug screening as well as for the development of biological compounds such as: vaccines, therapeutic proteins on a large scale. Figure 2. Primary cells can be grown either in suspension or adherent cultures. Some cells naturally live in suspension, without being attached to a surface for example those derived from peripheral blood.
There are also cell lines that have been modified to be able to survive in suspension cultures, they grow to a higher density than adherent conditions would allow. For the primary cells that are anchorage-dependent, adherent cells such as solid tissues require a surface to grow properly in vitro. The cell culture media is composed of a basal medium supplemented with appropriate growth factors and cytokines. The culture conditions widely vary depending up on the cell type.
Growth media can vary in pH, glucose concentration, growth factors, and the presence of other nutrients depending up on the cell types. During establishment of primary cultures, it is essential to include an antibiotic in the growth medium to inhibit contamination introduced from the host tissue. Antibiotics may include a mixture of gentamicin, penicillin, streptomycin and amphotericin B.
However, long-term use of antibiotics is not recommended, since some reagents such as amphotericin B may be toxic to cells on a long run.
It is very important to retain the viability of primary cells after isolation as most of them undergo the process of senescence and stop dividing after a certain number of population doublings.
For long-term viability of the cells excellent cell-culture handling skills along with appropriate culture condition i. Growth factors used to supplement media are often derived from animal blood the blood-derived ingredients possess the potential for contamination it is recommended to minimize or eliminate the use of these ingredients wherever possible.
Use of aseptic technique is also necessary. Cellular confluence generally refers to the percentage of the culture vessel inhabited by attached cells. It is an important and essential parameter to track and assess in primary cell culture as various cell types require different confluence end points, at which point they need to be sub-cultured. The maintenance phase of cells begins when isolated cells are attached to the surface of the culture dish.
Usually attachment takes about 24 hours after initiation of the culture. When cells reach a desired percent of cellular confluence and are actively proliferating, it is time to subculture. Anchorage-dependent cells grow in monolayers and need to be sub-cultured at regular intervals with appropriate culture medium to maintain exponential growth. Sub-cultivation of monolayers involves the breakage of both inter- and intracellular cell-to-surface bonds.
After the cell dissociation and dispersion into a single-cell suspension, they are counted and diluted to the appropriate concentration and transferred to fresh culture vessels the composition of the media varies depending up on the cell types where they will reattach and divide. Hemocytometers are commonly used for estimation of cell number and determination of cell viability using the exclusion dye Trypan Blue.
A hemocytometer is a fairly thick glass microscope slide with a rectangular indentation that creates a chamber. The chamber is engraved with a laser-etched grid of perpendicular lines and the device is carefully crafted. The area bounded by the lines and the depth of the chamber is known. Therefore, it is possible to count the number of cells in a specific volume of fluid, and thereby calculate the concentration of cells in the fluid overall. Cryopreservation is the process to preserve structurally intact living cells using low temperatures.
It is essential to cryopreserve and thaw primary cells in order to minimize cell damage and death during each process. In case of primary cells it is achieved with the use of a cryoprotectant, such as DMSO or glycerol at correct temperature and with a controlled rate of freezing. Precaution should be taken not to centrifuge primary cells upon thaw as they are extremely sensitive to damage during recovery from cryopreservation.
It is good to plate cells directly upon thaw, and allows cultures to attach for the first 24 hours. All Rights Reserved. Reproduction of any materials from the site is strictly forbidden without permission. Primary Cell Culture Basics. What are primary cells? Examples of commonly used primary cells used in biomedical research. Advantages and Disadvantages of Primary Cells Advantages Disadvantages Use of primary cells avoids many ethical objections raised against animal experiments.
Allows experiments on human tissues which otherwise could not have been done in vivo. Primary cells take more time to grow than other cell lines and have limited growth potential even under optimal growth conditions and eventually senesce and die.
The use of primary cells provides more relevant results than cell lines. Pre-screened primary cells are good models to represent the signaling in vivo very closely. The cells taken from different donors behave differently in response to pro-inflammatory cytokines unless they are pre-screened. The growth of metabolic regulatory mechanism that exist under in vivo conditions are absent in culture condition. Primary cells are cost-effective as they help reduce the expenditure on animal models required for in vivo studies The cost of isolation and culture is often high and prohibitive though cheaper that animal models.
The tissue culture may not be always possible. The characteristics of primary cells may change with each subsequent passage if optimum culture conditions are not maintained. Table 1. Overview of primary cell line characteristics. Primary Cells vs. Cell Lines Continuous cell lines have acquired the ability to proliferate indefinitely immortalized either through random mutation as in transformed cancer cell lines , or by deliberate modification such as artificial expression of cancer genes.
Comparison between Primary Cells and Continuous Cell lines. These cells can act as a model system to study cell biology and biochemistry, to study the interaction between cell and disease-causing agents like bacteria, virus , to study the effect of drugs, to study the process of aging, to study cell signaling and metabolic regulations. In many cases the use of primary cells allows the researchers to avoid the complications availability, cost and ethics involved in using animal models.
Thus, the mechanism and cause of cancer and the altered signaling pathways can be studied. It can also be used for determination of effective drugs for cancer cells. The side effects of cancer treatments chemotherapy and irradiation on normal cells can also be studied in this context. Primary cells are also useful to study the mode of infection. It is useful for the synthesis or production of a variety of biomolecules at an industrial scale. This is particularly useful in the pharmaceutical industry.
Primary culture is used as an alternative for animal models to test the effects of new drugs, cosmetics and chemicals. They are also used to determine the maximum permissible dosage of new drugs. Research is on-going on utilizing primary cells in the reconstruction of damaged tissue or replacement of non-functional cells or tissues.
Organ culture techniques and research are being conducted on both embryonic and adult stem cell culture. These cells have the capacity to differentiate into many different types of cells and organs. By controlling the development and differentiation of these cells, we may be able to treat variety of medical conditions.
Primary cells have also been used extensively in 3D bioprinting applications. This is an area that is being explored to design therapies for genetic disorders, spinal cord injuries, degenerative diseases and cancer. Cellular confluence Cellular confluence generally refers to the percentage of the culture vessel inhabited by attached cells. Maintenance and Subculture The maintenance phase of cells begins when isolated cells are attached to the surface of the culture dish. Cell counting Hemocytometers are commonly used for estimation of cell number and determination of cell viability using the exclusion dye Trypan Blue.
Cryopreservation and recovery Cryopreservation is the process to preserve structurally intact living cells using low temperatures. Primary Cell Culture Troubleshooting Contamination: Contamination of primary tissue when carried over to culture.
Shifts in pH: This may be caused sue to incorrect salt in the culture medium, bacterial or fungal contamination, insufficient bicarbonate buffering, incorrect carbon dioxide tension etc. Optimum adherence: Insufficient or absence of attachment factors in the medium or contamination or overly trypsinized cells. Precipitation: no change in pH : Precipitates in the medium without change in the pH may appear due to use of frozen medium, residual phosphate leftover while washing with detergent, which may precipitate powdered medium components.
Cell clumping: Suspension cell may clump due to presence of calcium, magnesium ions or due to cell lysis and release of DNA over digestion with proteolytic enzymes. Induced variability : Use of a variety of reagents and media induces variability in data acquired using primary cells.
The handling methodology between the users may also contribute to the variability. References Curr Protoc Cell Biol. Standardized cryopreservation of human primary cells.
A potential difference is created that can drive an electric current to do work. Electrochemical cells have very important commercial applications as a portable supply of electricity to power electronic devices such as mobile phones, tablets and laptops. On a larger scale, they can provide energy to power a vehicle. So, how do electrochemical cells like simple batteries work? How does a zinc—carbon battery work? How does a NiCad or alkaline battery work? How does a lead—acid battery work?
Your privacy is important to us. By submitting this form, you consent to AWM Network and up to 4 suppliers contacting you by email, web push, telephone incl. You have certain rights in relation to your personal data, including the right to object to direct marketing. Thank you for using GreenMatch. Solar energy produces power for households and businesses through solar panels, which contain solar cells that harness energy from the sun.
They offer some distinct advantages and improvements over other forms of battery technology. To gain the best from the li-ion battery technology, it is necessary to understand not only the advantages, but also the limitations or disadvantages of the technology. In this way they can be used in a manner that plays to their strengths in the best way. With lithium ion battery technology advancing at a very swift rate, the disadvantages are being addressed and the overall technology is being improved. There are many advantages to using a li-ion cell of battery. As a result the technology is being used increasingly for a huge number of widely varying applications.
Primary batteries are used once, then discarded. · A primary cell cannot be recharged whereas a secondary cell can be recharged. · The.
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Rechargeable batteries also known as secondary cells are batteries that potentially consist of reversible cell reactions that allow them to recharge, or regain their cell potential, through the work done by passing currents of electricity. As opposed to primary cells not reversible , rechargeable batteries can charge and discharge numerous times. Secondary cells encompass the same mechanism as the primary cells with the only difference being that the Redox reaction of the secondary cell could be reversed with sufficient amount of energy placed into the equation. The figure below illustrates the mechanism of a charging secondary cell.
Primary cells most closely represent the tissue of origin. They are taken directly from the tissue and processed to establish them under optimized culture conditions. Because they are derived from tissue and not modified, they are more similar to the in vivo state and exhibit normal physiology.
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Facts about rechargeable, secondary batteries. Advantages. Best solution for high Lower energy density than primary cells unless exotic chemistries used.Reply
Classification of Cells or Batteries.Reply
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Primary batteries are used once, then discarded. They have the advantage of convenience and cost less per battery, with the down side of costing more over the.Reply
Secondary (rechargeable) batteries can be recharged by applying a reverse current, (b) The battery is used as a primary battery would be but is then recharged Cell Voltage (V), Capacity (Wh/kg), Advantages, Disadvantages, Applications.Reply