Below is a list of our most common questions. Please feel free to reach out if you have any additional questions. We’ll respond to you as soon as possible 847-446-9986 or  info@bugcheck.us.


  • Do you have microbiological test kits or dip slides to detect algae?

No, our test kits and dipslides only detect bacteria, yeast, and mold. Algae are very slow growing organisms and require very complex growth media and incubation conditions.


  • Other than the expiration date, how can I tell if a dipslide is still acceptable to use for testing?

If the agar on the dip slide has not dried out and still remains intact, it will usually be acceptable to use.


  • Is a dip slide still acceptable to use for testing if it has not expired but the agar has dried out?

No, the dip slide is not acceptable to use.


  • What is the actual temperature that is required for incubation of the dipslides?

If you have an incubator, store the dipslides at approximately 30°C. If an incubator is not available, incubate the dipslides at room temperature (22-24°C or 72-75°F) by storing them in a warm location. If you are incubating the dipslides at room temperature, an extended incubation time is recommended (see the following FAQ).


  • The dipslide instructions specify an incubation period of 24-36 hours. How long should I incubate the dip slides?

If you are incubating the dipslides at room temperature, we recommend an incubation period of 36 hours. If you are incubating at 30°C, the dipslides can be read after 24 hours.


  • Do the dipslides need to be incubated in light or dark conditions?

Either environment is acceptable because the presence of light has no impact on the dipslide itself. But keep the slides out of direct sunlight. 


  • I incubated my dipslides longer than 36 hours. Is this a problem?

No, it is acceptable to incubate the dipslides for 48 hours or more. However, keep in mind that the longer the dipslides are left to incubate, the larger the colonies may appear on the agar surface. When large numbers of microorganisms are present, an extended incubation period may result in dipslides that are difficult to interpret.


  • I have larger dots on my dipslide. Does this mean I have more microorganisms?

No, the "dot" or colony size on a dipslide is independent of the number of microorganisms. If lower numbers of microorganisms are present, the colonies may grow in size on the dipslide but this does not always occur.


  • Some of my colonies on the dipslide are not red. What does this mean?

The colonies turn red on the dipslide because of the reduction of an indicator dye. This dye is added to the dipslide in order to aid the viewing of the colonies against the agar surface. Certain bacteria do not always reduce this dye which would result in an occasional colorless colony.


  • Are all colonies on the fungal side of a BF dipslide considered to be yeast or mold? Are all colonies on the bacterial side considered to be bacteria?

Specific agents are present in the fungal agar to inhibit the growth of bacteria. However, some bacteria are resistant to the inhibitors and may still appear on the fungal agar. The same is true for the bacterial agar. Certain inhibitors are present to deter the growth of fungi but some may still appear on the bacterial agar. If you are unsure of the interpretation of a dipslide, send us the item in question and we can determine what types of microorganisms are actually present. 


  • My dipslide surface turned red or pink almost immediately. Do I have lots of bacteria?

No, this is most likely a chemical reaction. The dye that is added to the media on the dipslide in order to color the colonies red, reacts when the sugar in the media is broken down. This reaction may be caused by bacteria or even by certain chemicals. If the color change is due to a chemical reaction, it should happen within the first 15-30 minutes. Also, no colonies would be visible on the dipslide surface within that time period.


  • How do I dispose of a used test strip or dipslide?

We suggest to soak dipslides and test strips in a 5% bleach solution for 30 minutes before disposal. This solution can be poured directly into the dipslide vial or the test strip incubation pouch. 


  • What does 10 to the 3rd, 10 to the 4th, 10 to the 5th etc. mean?

The superscript number specifies the power of 10. If a dipslide is interpreted to contain 103 microorganisms/mL, this means that there are 10 x 10 x 10 or 1000 microorganisms present. If 104 microorganisms are present, this corresponds to 10,000 microorganisms and so on.


  • Do the Bug Check Dipslides identify specific microorganisms such as Legionella or other pathogens?

Not necessarily. The identification of specific microorganisms is more complex and usually performed only within a microbiology laboratory.


For more information contact us by phone at 847-446-9986 or email us at  info@bugcheck.us



Stop the Stink with Sump Soda™ 

This coolant deodorizer is compatible with all major metalworking fluids:  Castrol, DA Stuart, Fuchs, ChemTool, Quaker, Houghton, Master, AW Chesterton, DoAll, ITW Fluids, Milacron, Hangsterfer's & others.

Comparative active ingredient toTriadine™ and Triazine.

Sump Soda™ is a bacteria killer.

How Do I Determine When My Coolant is No Longer Safe?

The following signs indicate that a coolant is no longer safe to use and might be hazardous to workers health:

  • Foul smell. Uncontrolled microbial growth causes metal working fluid to stink. It is important to address the cause of rancid smells, as the fine spray that is created during machining contains live microbes which can cause harmful health effects (dermatitis) in the employees who are exposed to this coolant mist.  Foul smelling fluid is likely caused by microbial growth and needs to be analyzed and treated with biocide. Coolant that cannot be saved should be discarded appropriately. Before adding fresh coolant, the sump needs to be thoroughly cleaned.

  • Abnormal fluid appearance. Check the color and appearance of the fluid regularly. Usually, synthetic fluids are clear, often the semi-synthetics appear transparent to milky, and soluble oil typically has a milky appearance with no oil layer. Bacteria often cause coolants to turn grey or black. Tramp oil may cause yellowing and browning of coolants. Colorless coolant is a sign of depleted coolant.  

  •  Employees suffer from respiratory irritation. Exposure to coolant mist that is contaminated by bacteria and fungal spores can lead to irritation and tightness in the chest.

  • Employees suffer from dermatitis skin symptoms from working with metalworking fluid, a persistent itchy rash that lasts six months or more.