The key difference between bioassay and chemical assay is that bioassay measures the concentration or activity of a substance by its effect on living cells or tissues while chemical assay analyzes a substance in a sample using a set of chemical procedures.
Assay is an investigative procedure which measures the presence/absence or the amount of an analyte in a sample or in an organism. Sensitivity, specificity, reproducibility, validity, repeatability and stability are characteristics of a good assay. There are several different assays as chemical assays, bioassays, microbiological assays and immunoassays. Bioassays utilize living cells or tissues to determine the activity of a substance, while chemical assay uses a set of chemical procedures to analyze a substance in a sample.
CONTENTS
1. Overview and Key Difference
2. What is a Bioassay
3. What is a Chemical Assay
4. Similarities Between Bioassay and Chemical Assay
5. Side by Side Comparison – Bioassay vs Chemical Assay in Tabular Form
6. Summary
What is Bioassay?
Bioassay is a procedure that determines the concentration or biological activity of a substance such as vitamin, hormone, and plant growth factors, etc. Usually, bioassays use living cells or tissues to detect the effects of substances and/or determine the potential toxicity of chemicals. In toxicology, bioassays are important in studying toxic substances and their effect on organisms and the environment. Moreover, bioassays are frequently done to monitor water quality and also sewage discharge and its impact on the surrounding. They are also used to assess the environmental impact and safety of new technologies and facilities. Some of the common bioassay examples are ELISA, home pregnancy test and HIV test.
Figure 01: Bioassay
In vivo bioassays determine the pharmacological activity of a substance by administering the test substance to a living organism. In vitro bioassays do not use living organisms. However, they depend on living tissues or cells, such as human cancer cell lines, etc. or enzymes. Microbiological assays are another type of bioassays. Bioassays should be reproducible. Bioassays can be quantitative or qualitative. Generally, a bioassay is done when the chemical assay is not available, too complex or insensitive. Bioassays are normally more expensive than chemical assays. Moreover, bioassays use biological tissues and lots of reagents. In addition, bioassays are time-consuming and produce less accurate results.
What is Chemical Assay?
Chemical assay is a set of chemical procedures that analyze a sample. Chemical assay can be a qualitative assay or a quantitative assay. Qualitative chemical assays determine physiochemical properties. They involve extractions, distillations, precipitation, etc. Quantitative assays determine volume or the amount of substances. Spectrophotometry, chromatography, spectrofluorimetry, gravimetry, colourimetry, turbidimetry and infrared spectroscopy are some chemical assays.
Figure 02: Chemical Assay
Chemical assays are more precise. They are less time-consuming. Moreover, they are less expensive and easy to handle, and less manpower is required. But compared to bioassays, they are less sensitive. In chemical assays, active constituent and structure are fully known. Chemical assays are used to determine the quality of raw materials in manufacturing processes. Moreover, organic chemical and solvents are tested using chemical assays.
What are the Similarities Between Bioassay and Chemical Assay?
- Bioassay and chemical assays are two types of assays.
- Both can be qualitative or quantitative.
What is the Difference Between Bioassay and Chemical Assay?
Bioassay is a method that determines the concentration or potency of a substance by its effect on living cells or tissues while chemical assay is a set of chemical procedures that analyze a sample. So, this is the key difference between bioassay and chemical assay. Active constituent and the structure are known in chemical assays while active constituent and structure are not known in bioassays.
Moreover, another difference between bioassay and chemical assay is that bioassays are more sensitive than chemical assays.
The below infographic tabulates more differences between bioassay and chemical assay.
Summary – Bioassay vs Chemical Assay
Bioassay and chemical assay are two types of assays. Bioassays determine the concentration or activity of a substance on living tissues, cells or organisms. Chemical assays analyze a sample using a set of chemical methods. Chemical assays are easy to handle compared to bioassays. Moreover, chemical assays are less time consuming and less expensive than bioassays. However, chemical assays are less sensitive than bioassays. Thus, this is the summary of the difference between bioassay and chemical assay.
Reference:
1.” Assays, Types Of Assays, Principle And Prerequisites Of Assays And Bi…”. Slideshare.Net, 2020, Available here.
2. “Bioassay”. En.Wikipedia.Org, 2020, Available here.
Image Courtesy:
1. “ELISA Plate image” By Kim.kan – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Spectrophotometric determination of the acidity constant of an acidic basic indicator” By Veronika emilova96 – Own work (CC BY 4.0) via Commons Wikimedia