What are the different types of streak plate method?

The four types of streak plate methods are quadrant streaking, continuous streaking, T-streaking, and radiant streaking. 

1. The most widely used type is the four-quadrant streak method, which streaks four equal sections. Each section receives a progressive dilution of the inoculum. The first election receives the highest concentration, while subsequent sections contain gradually diluted inoculum. As the process proceeds to the fourth quadrant, the inoculum becomes significantly diluted, allowing isolated colonies to form after incubation. A sterilizing loop is typically used between each quadrant to avoid cross-contamination (unless the bacterial load is very low). While this method is widely used, it is limited to utilizing only one sample per plate. 
2. The three-section streak method is a technique which divides an agar petri plate into 3 sections, forming a T shape on the plate. Each section is streak sequentially with the inoculum. This method involves streaking each adjacent section one after another. The first section receives the highest concentration of inoculum, while subsequent sections receive progressively diluted inoculum. The inoculating loop is typically sterilized between each section, however, if the specimen is highly diluted, a continuous streaking method can be used. This method is also  limited to utilizing only one sample per plate. 
3. The continuous streaking method is a simple technique where the inoculum is uniformly spread across the agar plate in a continuous motion from the plate’s periphery towards the center. It is not required to divide the plate or sterilize the loop during the proceeds, making it easy and rapid to use. This technique is effective when the inoculum is highly diluted or when the goal is to grow pure culture rather than isolate a specific organism. Diving a 10 cm petri plate into multiple sections (usually 2-6) allows for streaking different specimens in each section. Labs typically use this approach when multiple samples such as urine and sputum need culturing concurrently. 
4. Radiant streaking is a technique in which the inoculum is initially streaked at one edge and spread in vertical lines above the edge. Afterward, these vertical lines are crossed by streaking diagonally. This technique is effective for growing pure culture and can also be used with diluted specimens.