Troubleshooting  

Helpful safety hints for this experiment:

*Always wear gloves, goggles and protective footwear when working in a lab with dangerous chemicals like the ones used in this experiment.

*When performing chemical tests, always be sure to rinse pipets and stirring rods after each use so you do not mix chemicals and to avoid contaminating test results.

*Always label plastic bags, test tubes and petri dishes before putting soil or any other substance in them so you do not get confused as to which sample is which.

*When extracting soil from a wooded area, be sure to apply sunscreen and bugspray and wear appropriate clothing depending on the climate and weather conditions in which you live. Long pants and long-sleeved shirts are always helpful.

*Always check yourself for ticks when you come back from the woods.

*Always use sterile water and pipets for serial dilutions.
 
*When working with microorganisms, always use proper sterile protocol; be sure to wipe down your lab station with rubbing alcohol after you are finished all chemical testing.

*Most of the time, if a sample is accidentally dropped, it is better to have a lost data point than to go back outside and collect a new sample.
 
*When you are shaking tubes during serial dilutions, if soapy bubbles appear, this means that your tubes were not cleaned properly, and you must start over with that sample.

*When counting the total number of protozoa, remember to round to a whole number because you can't have a fraction of a protozoa.

*If a chemical ever comes in contact with your skin, be sure to follow the safety precautions on the bottle of that particular chemical and to notify a responsible adult.