9,292
edits
BISC209/F13: Lab2: Difference between revisions
From OpenWetWare
Jump to navigationJump to search
→RICHNESS OF A MICROBIAL SOIL COMMUNITY: METABOLIC DIVERSITY: Structural Diversity in Cultured Bacteria from a Soil Community
Tucker Crum (talk | contribs) |
Tucker Crum (talk | contribs) |
||
| Line 86: | Line 86: | ||
<ul> | <ul> | ||
<LI>Flame your loop, let it cool a few seconds. Remove or tilt the lid of the donor agar plate with your non-dominant hand but keep the lid in your hand (don't put the lid down on the bench!). With your dominant hand holding the flammed and cooled loop, touch the loop to an interesting colony of bacteria that you want to study and pick up a TINY amount of the colony. Avoid touching other bacterial colonies. Close the lid of the donor plate. | <LI>Flame your loop, let it cool a few seconds. Remove or tilt the lid of the donor agar plate with your non-dominant hand but keep the lid in your hand (don't put the lid down on the bench!). With your dominant hand holding the flammed and cooled loop, touch the loop to an interesting colony of bacteria that you want to study and pick up a TINY amount of the colony. Avoid touching other bacterial colonies. Close the lid of the donor plate. | ||
<Li> | <Li> TIlt the lid of a new sterile plate of solid medium (in this case it will be Nutrient Agar) with your non-dominant hand so that it is partially open. Do not put the lid down on the bench; keep it in your hand! Touch the loop with the bacteria to the surface of the agar in an area near the periphery of the plate and gently glide the loop over the innoculum to spread it over a small area of the plate called Section 1 as shown in the illustration below. Do not gouge the agar! Replace the lid. | ||
<li> | <LI>Flame your loop and let it cool for a few seconds. | ||
< | <li>Tilt the lid of the plate so it is partially open and drag your loop once or twice through the area you have just innoculated (section 1) and spread the innoculum you picked up across the surface of a new section of the plate. This section is called Section 2. | ||
<li> | <li> Flame and cool your loop. | ||
<li>Check your plate for colonies daily and record your descriptions of the texture and shape of the colonies that appear. If any colonies arise that look tough and leathery or appear as "little, powdered-sugar volcanos", use the tip of a sterile toothpick to pick up a small but visible amount of growth (being careful not to touch anything but the tip of the colony) and "spread" the bacterial growth onto section 1 of a new | <li>Repeat to streak sections 3 and 4 by dragging your loop through the last section innoculated once or twice and then to a new area of the plate. Replace the lid. | ||
<li>Label the recipient plate on the bottom (NOT the lid!), invert it, and incubate the plate at RT. | |||
<li>Check your plate for colonies daily and record your descriptions of the texture and shape of the colonies that appear. If any colonies arise that look tough and leathery or appear as "little, powdered-sugar volcanos", use the tip of a sterile toothpick to pick up a small but visible amount of growth (being careful not to touch anything but the tip of the colony) and "spread" the bacterial growth onto section 1 of a new nutrient agar (NA) plate. Only inoculate one colony/plate and streak for isolation into 4 sections as described above. | |||
</ul> | |||
Over the next few weeks you will continue to sub-culture onto new plates, using your best isolation streak technique. Your goal is to continue to streak out ONE CFU until you are sure that all the bacterial growth in a colony comes from a single mother cell (pure culture). In subsequent labs you will make a bacterial smear and do a Gram stain of these genetically identical bacteria and you will perform other tests from freshly pure cultures to explore the physical and metabolic characteristics of this isolate. <BR><BR> | Over the next few weeks you will continue to sub-culture onto new plates, using your best isolation streak technique. Your goal is to continue to streak out ONE CFU until you are sure that all the bacterial growth in a colony comes from a single mother cell (pure culture). In subsequent labs you will make a bacterial smear and do a Gram stain of these genetically identical bacteria and you will perform other tests from freshly pure cultures to explore the physical and metabolic characteristics of this isolate. <BR><BR> | ||
