Chapter 1. Common laboratory tools and equipment used in biochemistry and molecular biology

by László Radnai

Table of Contents

1.1. Biological samples and chemical substances in the laboratory
1.2. Plastic and glass tubes used for the storage of liquids
1.3. Beakers and laboratory flasks
1.4. Precise volumetric measurements with graduated cylinders and micropipettes
1.5. Mixing of liquids
1.6. Laboratory balances
1.7. Methods of sterilisation and in-house production of high-purity water
1.8. Working with cell cultures
1.9. Centrifuges
1.10. Other widely used laboratory techniques: spectrophotometry, electrophoresis, chromatography
1.11. Storage of biological samples

The aims of biochemical and molecular biological research are complex and diverse. Investigation of the network of chemical reactions taking place in living organisms and representing the most fundamental phenomena of life, identification of the molecules playing roles in biochemical processes, determination of their structure, function and interactions, examination of the molecular background of metabolism, the flow of energy and information within organisms are all among the common goals of biochemists and molecular biologists. In accordance with this diversity of problems, a high variety of tools, instruments and methods are required to answer scientific questions effectively. This chapter reviews the most common tools and instruments used very frequently in almost every laboratory. The appropriate handling and storage of biological samples and other chemical substances required for research will also be discussed.

1.1. Biological samples and chemical substances in the laboratory

Tissue or cell samples from a living organism, different cell cultures grown in a laboratory incubator under controlled conditions, homogenates or extracts of cells and tissues, solutions of isolated and purified components (e.g. proteins, nucleic acids) can all be referred to as “biological samples”. As the medium of life is water, the majority of biological samples can be defined as aqueous solutions with one or more components, colloidal systems, or water-based suspensions (e.g. bacterial cells dispersed in a liquid medium). Consequently, most biochemical experiments also take place in aqueous environments. Therefore, laboratory vessels used to store liquids and laboratory tools required for the manipulation, transfer and accurate volume measurements of liquids will be introduced in this chapter. Different solids (e.g. chemical substances obtained from different companies, synthetic oligonucleotides or peptides) are also often necessary for biochemical research. In most cases, solids are dissolved in water (or sometimes in other solvents) prior to the experiments. Therefore, the methods of preparing solutions and measuring accurately the weight of the required solids will also be discussed below. Sometimes we use gases in the laboratory. These can be stored in gas cylinders (e.g. O2), in Dewar flasks in liquid state (e.g. liquid nitrogen), or dissolved in water (e.g. HCl or NH3). By working with gases it is very important to follow all safety instructions to avoid fire, explosions, frostbite or (in case of inhalation) asphyxia or poisoning.