Lab Techniques

From Phyco.org

Common lab techniques, materials, and equipment and their uses in the lab are described below.

Contents 1 Chemicals 1.1 Handling 1.2 Common Chemicals around the Lab 1.3 Water 1.3.1 Tap 1.3.2 De-Ionized (DI) 1.3.3 Distilled 1.3.4 Filtered 1.3.5 RNAse-free (Biochemistry-grade) 2 Sterile Technique 2.1 Equipment & Use 2.1.1 Autoclave 2.1.2 Sterile Hood 2.1.3 Bunsen Burner 2.1.4 Ethanol 2.2 Maintaining Sterilization

[edit] Chemicals

[edit] Handling

All lab chemicals should have an associated Material Safety Data Sheet (MSDS).

[edit] Common Chemicals around the Lab

• Reagents
• Acids & Bases
• Solvents

[edit] Water

There are several varieties of water used around the lab.

[edit] Tap

High in minerals. It is recommended to rinse out labware three times with tap water, followed by three rinses of DI water.

[edit] De-Ionized (DI)

Water that has had its minerals and salts removed through an ion exchange resin filter or an electrodeionization process. It is effective for cleaning labware, as it will rinse off ions and chemicals, without leaving residue or spots, when put onto a rack to dry. DI water can also be tested for the presence of minerals using a resistivity meter; the absence of mineral and salt ions greatly reduces the conductivity and increases resistivity of water. It is not recommended to drink, as it will dilute ionic concentrations within the body, and cause health problems.

[edit] Distilled

Heated and condensed

[edit] Filtered

Reverse osmosis

[edit] RNAse-free (Biochemistry-grade)

Expensive

[edit] Sterile Technique

Sterile environments are important to maintaining optimal growth conditions for a single strain of algae, as well as in experimentation. Contamination of cultures can cause unknown variables to enter the experiment. In photobioreactors, the end biomass output may be diminished. ^{(citation needed)}

[edit] Equipment & Use

[edit] Autoclave

An autoclave is an instrument with a metal vessel that sterilizes using steam, high heat, and pressure. For the sterilization of glassware, equipment, liquids, as well as the preparation of agar and media, autoclaves are indispensable. Autoclaves usually operate at around 2 atmospheres and 121-134C (250-268F) for periods of up to 18 minutes, depending on temperature and degree of sterilization desired. ^{(citation needed)} To keep track of autoclaved materials, a sticker can be applied that changes color in the presence of steam.

[edit] Sterile Hood

[edit] Bunsen Burner

[edit] Ethanol

A spray bottle containing a solution of 70% EtOH with DI H₂0 is often sufficient for the disinfection of lab surfaces. Used to disinfect a sterile hood before use.

[edit] Maintaining Sterilization

Culture media, once prepared, must be handled carefully. It is best to use a glass container and a cap with an airtight seal. Always handle in a sterile hood, after spraying the bottle with ethanol (the inside is sterile, but once removed from the autoclave, the outside surface of the container is contaminated), and carefully passing the opening of the glass container over a bunsen burner (a process sometimes known as 'flaming the lip'). Heat sterilization is useful because not only does it sterilize on contact, the surface remains heated for some time, and air flows out of the vessel rather than in. Refrigeration of culture media is not always required, however, it is recommended.