Category: Laboratory Techniques

Introduction Plant tissue culture allows propagation of disease-free plants from small explants in artificial media. Success depends almost entirely on aseptic technique — excluding bacteria, fungi, and yeast from cultures. Contamination typically appears within 3–7 days as cloudy media, fungal mats, or bacterial swarming. Why contamination spreads so fast Rich culture media (sucrose, amino acids,…

From tissue to clear images Microscopy reveals cell walls, chloroplasts, stomata, and vascular bundles. Poor preparation crushes cells or leaves air bubbles that obscure detail. Fresh hand sections Use a sharp razor or double-edged blade on moist tissue. Support material in carrot or potato pith to stabilize thin stems. Sections should be 0.5–1 mm thick…

Optical principles Compound microscopes use two lens systems: objective (4×, 10×, 40×, 100× oil) and eyepiece (usually 10×). Total magnification = objective × eyepiece. Lighting and contrast Adjust iris diaphragm — too much light washes out unstained tissue; too little reduces resolution. Kohler illumination aligns light path for even brightness. Structures to identify in leaf…

What culture media provide Explants lack roots for water uptake and leaves for photosynthesis initially. Media supplies minerals (MS basal salts), carbon (sucrose), vitamins, and growth regulators (auxin, cytokinin). Murashige & Skoog (MS) medium Industry standard for many species. Macronutrients (N, P, K, Ca, Mg, S) and micronutrients (Fe, Mn, Zn, etc.) at defined concentrations.…

Autoclave operation Autoclaves use pressurized steam (121°C, ~15 psi) to kill all life stages including spores. Liquids need slow exhaust to prevent boil-over; dry goods use fast exhaust. Load arrangement Do not pack tightly — steam must circulate. Use indicator strips that change color when sterilization conditions are met. Chemical safety Label all bottles with…

Why documentation matters Experiments cannot be reproduced or published without traceable records. A lab notebook is a legal document in research settings. Minimum entries per culture experiment Date, operator name, plant species and source Media recipe and lot numbers of chemicals Explant preparation method and disinfectant protocol Environmental conditions (light hours, temperature) Outcome: contamination rate,…