INCULATION TECHNIQUES Inoculation is planting inocula aseptically into sterile media. Inocula is a material that contains microbes or microbial cultures, either in liquid or solid state. Inoculation can be carried out on solid media (by scratching or puncturing), as well as on liquid media. In general, this inoculation has several objectives, namely as follows: • Enrichment of microbial viable cells • Purification or obtaining specific colonies • Observation of microbial characteristics, for example motility using medium, biochemical tests, resistance tests, Camp tests, etc • Microbial counting Microbes rarely occur in nature in a pure state. Most are a mixture of various microbial species. Separation can be done through various microbial isolation and cultivation techniques, including: a) Spread Plate (seedling method) Spread plate is a planting technique by spreading a bacterial suspension on the surface to obtain a relatively even culture so that it can be counted. In the spread method, a certain amount of culture (generally 0.1 - 0.5 mL) is spread on the surface of the agar, using a sterile spreader (bent rod). The cup is then incubated at the required temperature and time. b) Pour Plate (pour method) This technique requires agar that is not yet solid (>45oC) to be poured with the bacterial suspension into a Petri dish and then homogenized and allowed to solidify. This will spread bacterial cells not only on the surface of the agar but also cells submerged in the agar (inside the agar) so that there are cells that grow on the surface of the agar which is rich in O2 and there are those which grow in the agar which contains less oxygen. c) Planting Technique with Streaks The scratch planting technique aims to isolate microorganisms from the mixture or rejuvenate (enrich) the culture into a new medium. i. Continuous Scratch The work procedures carried out are as follows: • Touch the inoculum loop (Ose needle) on the colony or microbial suspension and Scratch continuously until half the surface of the agar. • Do not ignite the loop, then rotate the cup 180oC, continue the stroke until it runs out. ii. T scratches • Divide the cup into 3 parts using a marker • Inoculate area 1 with a zig-zag streak • Heat the inoculant needle and wait for it to cool, then continue the zig-zag streak in area 2 (streak in the picture). The cup is rotated to get a perfect streak • Do the same thing in area iii. Quadrant Streak (Streakquadrant) • Almost the same as the T stroke, but with a different stroke pattern, namely divided by four. • Area 1 is the initial scratch so it still contains many microorganism cells. • Subsequent scratches are cut or crossed from the first scratch so that the number decreases and eventually separates into a single colony. iv. Smear Technique (Swab) This technique is basically the same as the scratch technique using an Ose needle or loop, the only difference is that the tool used in this technique is a swab (a kind of sterile cotton bud). v. Oblique Agar Inoculation • Prepare the culture, slant agar media and loop needle. • Turn on the Bunsen burner / spirit lamp and burn the ose until it is red hot. • Once the desired culture sample has cooled, scrape the sample onto the basesurface so that it slopes upwards in a zig-zag pattern