The majority of laboratory practices utilised in the In Vitro propagation of plants are easily learned. The important things to concentrate on are on accuracy, cleanliness, and strict adherence to details when performing in vitro techniques. The preparation of media requires careful weighing of all its components. Even if a commercially prepared Medium is used, care must be taken in preparing it and any stock solutions that you require.

Weighing

The types of balances most often encountered in the laboratory include top-loading single-pan balance, triple-beam balance, double-pan torsion balance, analytical single-pan balance, and top-loading electronic balance. The last type has become quite popular in recent years due to its accuracy, ease of use, and durability. With a lot of top-loading electronic balances, milligram accuracy is now possible. Such accuracy previously required the use of analytical balances. A good quality top-loading electronic balance can be purchased for around $250US for home use that weight with milligram accuracy.

There are several precautions that must be observed to obtain accurate weights. First, the balance should be located on a hard, stable, level surface which is free of vibrations an excessive air drafts. The balance and weigh area should always be kept clean. Most importantly, the balance should never be overloaded. Always check the manufacturer’s specifications. Use a lightweight weighing container or paper rather than placing the material to be weighted directly on the pan surface.

Measuring Liquids

Calibrated glassware such as beakers, flasks, and pipettes are required for the preparation of media.

Graduated cylinders of 10, 50, 250, and 1000-ml capacities are essential for many measuring operations. The volumetric flasks and pipettes are required for more precise measurements. Measurement of solutions with pipettes or graduated cylinders is only accurate when the bottom of the curved air-liquid interface is aligned with the measuring mark (Meniscus). Pipettes are best filled by a hand-operated device, called a pipettor, which eliminated the hazards of pipetting by mouth.