When quantifying microbial populations and growth, it is important to pick the right method. Understanding the advantages and disadvantages of each method with various types of samples can mean the difference between valid and meaningful data and a failed experiment. Many times, especially with environmental samples, it is best to use multiple methods to quantify the same sample to increase the validity and reliability of the results. Match the samples below with the method of bacterial quantification that is best suited to that type of sample. There are many more methods available than those listed here, but let us start the discussion with these three. Part Aa. lake waterb. broth culture of E. colic. soil suspensionPart B1. direct microscopic counts of a DAPI-stained, filtered sample.2. viable plate count3. optical density