zones of .......

there are many zones in micro. Make sure you use the correct one
zones of hydrolysis = clear zone produced by hydrolysis of some compound ex lipid
zones of sensitivity = zone of no growth around antibiotic disc
zones of resistance = zone of growth up to antibiotic disc, in effect no zone
zones of clearing = usually used when talking about DNAse activity
zones of haemolysis = clear zones produced by haemolytic orgs, usually beta haemolysis

nutrient gelatin hydrolysis

gelatin has properties of solids at 4 deg and liquids at 37 deg. After inoculation and incubation, all tubes are liquid. We are trying to determine whether the org produces gelatinase, which will degrade the gelatin. After removing from the incubator, place in a fridge for 20 min. REmove and then read as follows:
solid = negative for gelatinase activity
liquid = positive for gelatinase activity
NB! Even a little liquid or semi solid appearance is positive

so what happened and why??
orgs that produce gelatinase break down the gelatin, so it will not solidify at 4 deg. Gelatin will liquify at 37 deg, and solidify at 4 deg, so is solid when removed from fridge.

stupid ways to learn... and other tricks

so much of micro can be learnt in a few minutes. Why don't you try:
1. make crib cards with names of orgs and relevant biochemical reactions, etc
2. labelled drawings of Gram reactions, shape and arrangements
3. Create A4 pages with really important stuff and stick on places much frequented, like door of bedroom, cover of notebook, etc (nad here's a classic one that always works, back of toilet door...... you laugh!!!)
4. Sing a song of.... names of orgs in full
5. Make up swear words/phrases that incorporate all relevant biochemical reactions/ uses of media/reactions seen on media, etc
example
you mannitol CHO fermenting S aureus, salt loving halophile you
back off S epidermidis, your mother was a salt lover; you are so pathetic you can't even ferment mannitol
I am so shy I turn pink when ever Mac comes near me. He always wants me to go to that new TSI club, but I find that the fluorescent lights there make my hair turn yellow.

as Bushknife Bobby would say:
hold me hold me; You wanna dalla with my DNA broer, I'll wys u how the DNA is degraded. Warrheid, hey u choon this litie how its done. See ere, you slaan the 1N HCl there, park in the shade,broer, and then pour of the excess HCl. Now you can eyeball the darkies. I am not a skaapie, ekse!!

comments please

success in a microbiology practical

everytime I see certain things done by you, I cringe; and tell myself afterwards that I really must spend a lesson on "correct" etiquette, but that goes the way of all good intentions. Finally I have a way, so here goes:

read the practical guide at least once before the prac.
make short notes on what you will be doing. I am not talking about complete sentences here, but rather diagrams showing type of media, name of orgs to be used,and any other pertinent info.
bring that info with you to the prac.
nothing irritates more tha students writing down stuff from the board, with no idea of whats cutting..... oh yeah, and students not doing anything!

please remember the golden rules:
share orgs
do your own inoculations, unless told otherwise
have your own marker
don't leave stools out unless a butt is on it; thay are safety hazards
know in advance how to use slant, broth and agar plate cultures

discarding of anything
sharps in a sharp container (in not visible, ask lab technician)
glass tubes in discard basket for autoclaving and re-using
plastic tubes and agar plates in biohazard box
ask yourself: can it be washed, autoclaved and re-used? if yes, then in disinfectant jars at front of benches or discard basket. if no, then biohazard box.

unless paper towel has been used for wiping up spills, it goes into waste paper bin, not biohazard.

take or collect all your media at the beginning of the prac.
same applies for cultures.

if you do not flame your loop adequately, you will contaminate your media. Adequate means till the loop and wire portion gets red hot.

do not wander around looking lost; it only entices me to call you or ask you difficult questions.

a word of advice here:
always know what you are doing, or cultivate the art of looking like you do. If not, I will certainly notice, and then its tickets for you.

enough for now. Please could I get some comments here, if you read this? thanx, mcuh appreciated