Total coliform bacteria test is an easy method with The LaMotte 4-3616 Coliform Test Kit. It Contains 5 disposable tubes and a water sample bag. Each of the tube contains a nutrients tablet that supports the growth of coliform bacteria, a gelling substance, and a pH indicator. If the coliform bacteria are present in the water sample then the bacteria metabolizing the nutrients in the tablet and generated gas. This gas will get stuck in the gelling substance and the gel will rise in the tube. The pH indicator will change the color of the water from red to yellow as further evidence of coliform bacterial activity. The higher the number of positive results in the supply tube, the greater the risk of serious bacterial infection. The test required a 44-48 hours to get the result.
Total coliform bacteria are a collection of different types of bacteria in water, soil, human or animal waste. Most of them are harmless. Detection of these bacteria in drinking water or water sources is very important because the presence of total coliform bacteria is an indicator of possible contamination. Consequently we can easily move forward to solve the problem. If only the total coliform bacteria are present in the water and fecal coliform bacteria are absent; This indicates that the source is probably environmental (portable water).
Method of Total coliform bacteria test by LaMotte 4-3616 Coliform Test Kit
- Sample collection: First you have to collect water sample in the supplied water sampling bag with the LaMotte 4-3616 Coliform Test Kit. Note that the bag contains a tablet rich in dechlorinating agent (2-2197), which is provided to neutralize any chlorine present in the water. Chlorine helps to suppress the growth of coliform bacteria. The outlet at the source of the sample should be cleaned and erased during sample collection and the sample collection bag should not be touched on the inside so that bacteria cannot enter the sample from outside.
- Allow the tap (cold water) to run for 2 to 3 minutes or until the line is flush. Reduce the flow of tap water at such a rate that water can be collected in the sampling bag without spraying water. Now tear off the top of the bag in the scored line and pull the tabs outwards to open the bag. Do not touch the inner surface when opening the bag.
- Fill the bag up to 4 oz field line. Pull the wire ends to close and whirl the bag for three complete revolutions. Shake the bag to dissolve the tablet.
- Remove all 5 tubes from the display package and open the caps. Unwhirl the bag and pull the tabs outward to open the bag. Fold the inside of a tape wire to form the spout. Carefully fill all 5 tubes up to the 10 ml line with the water sample. Replace the caps tightly. Do not mix or shake the tubes.
- Stand the carton straight and carefully place all 5 tubes in the display package. Make sure all the tubes are standing vertically. The tablet should lie flat on the bottom of each tube.
- Store the tubes at room temperature for 44-48 hours without direct sunlight. The air temperature should be fairly constant and between 70°-85°F (21°-29°C). While the tubes can be incubated at room temperature, incubation at 44.5° C (112° F) will accelerate growth and result in a more rapid test result. Do not disturb or shake the tubes during the scheduled incubation period. If these storage conditions are not followed properly, then the total coliform bacteria test results may not be appropriate.
- A positive result in any one of the five tubes should be considered as a potential coliform bacterial contamination. Both yellow color and gas bubbles must be present for positive test results. You should remember that yellow color without gas bubble does not indicate the presence of bacteria. If any positive results are found in two or more tubes, there is a possibility of a serious bacterial infection problem. Further steps should be taken to validate these results by a certified ad bacteriological laboratory.
After recording the results of total coliform bacteria test dispose the inoculated tubes by treating with chlorine bleach. Dispose of the LaMotte 4-3616 Coliform Test Kit tubes and package as required by local jurisdiction. Do not reuse the tubes for the test of total coliform bacteria.
Questions & answers
Q. Is the product for a single test or 5 different tests?
Answer: The 5 vials of the kit are for a single test. You should know that a positive result can be found in any one of the five tubes. One positive result considered as a possible coliform bacterial contamination whereas two or more positive results considered as a possibility of a serious coliform bacterial contamination.
Q. Can I use the kit to test for fecal coliform?
Answer: No, It only tests if coliform is present or absence in the water sample.
Q. Can it count how many total coliform are present ?
Answer: No, it does not count how many total coliform are present in the water sample. We can just idea if the sample water has serious or low coliform bacterial contamination. The higher the number of positive results in the supply tube, the greater the risk of serious bacterial infection.
Q. Is the LaMotte 4-3616 suitable for testing pool water?
Answer: Yes, you can use The LaMotte 4-3616 Coliform Test Kit for testing pool water. It can only show the presence or absence of coliform but does not shows how many total coliform are present in the supplied water.