Microbiology @ IHS Laboratory (BioLab).
The BioLab is equipped to analyse and test for microbial contamination of water. Various plate count tests are available to estimate bacterial colony forming units (cfu), which is a measure of the total bacterial population in a water sample. Multiple tube dilution techniques are used to estimate most probable number (MPN) of coliforms, some of which indicate environmental and faecal contamination of water. Confirmatory tests are available to identify indicator organisms associated with environmental and sewage contamination. The bacterial endotoxin assay is available to test the level pyrogens (endotoxins) in water for dialysis.
The plate count methods rely on growth of bacterial colonies on a variety of nutrient mediums incubated at specific temperature for various durations, so that colony becomes visible to the naked eye. But too many colonies, some of which may coalesce with each other would be difficult to count. Hence multiple petridishes with chosen nutrient medium are inoculated with different dilutions of test sample and the colony count is multiplied by the dilution factor.
In the most probable number (MPN) tests, rows of tubes containing lactose broth are inoculated with water samples measuring 10 ml, 1 ml, and 0.1 ml. During incubation, coliform organisms, if present, would produce gas. A small inverted tube (Durham tube) is placed in each test tube to capture as gas is produced by coliform bacteria. Durham tubes float when filled with gas. The number of test tubes in each row, showing definite signs of gas production is identified and a statistical table is used to arrive at the point estimate and range of coliform bacteria in the sample.
The bacterial endotoxin test (BET), based on the fact that the blood of the horseshoe crab (Limulus or Tachypleus) gels or clots when it comes in contact with endotoxin. The Limulus amebocyte lysate (LAL) reagents are used to test for endotoxin using gel-clot method.
The IHS Laboratory is accredited by the National Board of Accreditation for Testing and Calibration Laboratories (NABL) India.
Lab Id: T-4179; Certificate Number: TC-7658; Issue Date: 06-08-2022; Valid Until: 05-08-2024.
The IHS Laboratory is gradually developing itself as an easily accessible Public Health Laboratory for laboratory tests that are relevant to safeguarding and improvement of people’s health. Keeping with this objective, new test services are introduced to meet felt needs. The IHSL follows sound quality assurance mechanisms and adopts standard test methods for all tests including newly introduced tests. However, immediate accreditation by NABL may not be feasible, for various reasons. Thus, at any point of time, the laboratory would have a set of NABL accredited parameters, and other parameters for which NABL accreditation is not yet available. To avoid any misrepresentation, the IHSL we adopt a strict policy of using NABL symbol in test reports only if all test results included in the report are within the scope the accreditation. For more details see;
The IHSL Policy for Use of NABL Symbol and Claim of NABL Accreditation on Test Reports.
BioLab - Scope of Service
Test Parameters Accredited by NABL, vide certificate number TC-7658, date 06-08-2022, valid until 05-08-2024.
|Sl||SvCd||Parameter||Test Material||Test Method|
|SPC||Standard Plate Count||Drinking Water, Water for Food Processing, Water for Dialysis, Purified Water, Groundwater, Irrigation Water, Surface Water, Swimming Pool Water.||IS 1622 Nutrient agar & 24h incubation at 37℃.|
|AMC||Aerobic Microbial Count||Water from Purifiers.||IS 14543 read with IS 5402: Plate count agar & 24h incubation at 37℃.|
|TVC||Total Viable Count||Water for Dialysis, Purified Water.||IS 23500 part 3 Tryptic soy agar & 48h incubation at 35-37℃.|
|HPC||Heterotrophic Plate Count||Drinking Water, Package Drinking Water, Water for Food Processing, Water for Dialysis, Purified Water, Groundwater, Irrigation Water, Surface Water, Swimming Pool Water.||IS 5402 Plate count agar & 72h incubation at 30℃.|
|BET||Bacterial Endotoxin Assay (LAL)||Water for Dialysis, Purified Water.||Indian Pharmacopoea|
|MPNTC||MPN (Total Coliforms)||Drinking Water, Water for Food Processing, Water for Dialysis, Purified Water, Groundwater, Irrigation Water, Surface Water, Swimming Pool Water, Wastewater.||IS 1622 3.3.1 Multiple tube dilution test (MDT)|
|TTC||Thermotolerant Coliforms||Drinking Water, Water for Food Processing, Water for Dialysis, Purified Water, Groundwater, Irrigation Water, Surface Water, Swimming Pool Water, Wastewater.||IS 1622 - 18.104.22.168 subculture, from one presumptive positive tube of coliform test, in BGLB at 44℃ for 24h.|
|ECOLI||E. coli||Drinking Water, Water for Food Processing, Water for Dialysis, Purified Water, Groundwater, Irrigation Water, Surface Water, Swimming Pool Water, Wastewater.||IS 1622 - 3.3.4 subculture, from one presumptive positive tube of coliform test, in tryptone water at 44℃ for 24h.|
|MPNTTC||MPN (Thermotolerant Coliforms)||IS 1622 - 22.214.171.124 subculture, from all presumptive positive tubes of coliform test, in BGLB at 44℃ for 24h.|
|MPNEC||MPN (E. coli)||IS 1622 - 3.3.4 subculture, from all presumptive positive tubes of coliform test, in tryptone water at 44℃ for 24h.|
Water Sample Collection Bottles for Bacteriological Analysis:
|CSB||Clean Sterile Bottle||Clean sterile rigid polypropylene bottle without any additive.||250ml|
|SBT||Sterile Bottle with Thiosulfate||Sterile rigid polypropylene bottle with sodium thiosulfate to neutralise chlorine, for bacteriological analysis (coliform test) of water.||250ml|
|SBTE||Sterile Bottle with Extra Thiosulfate||Sterile polypropylene bottle with extra sodium thiosulfate to neutralise excess chlorine, for bacteriological analysis of pool water.||250ml|
|NPT||Non Pyrogenic Tube||Non-pyrogenic glass tube to collect water sample for bacterial endotoxin test (BET) i.e. LAL assay.||14ml|