Introduction Medical instruments are routinely sterilized using autoclave or by gas sterilization using ethylene oxide. However this method of sterilization is insufficient to destroy pyrogen because it is thermostable as a matter of fact, pyrogens will be formed from the dead gram-negative bacteria that is killed during the sterilization process. The pyrogen substance that is produces is called endotoxin. Medical instruments (such as surgical instruments and in certain cases of implants) may contain endotoxin on the surface of the instruments, due to this the LAL test is performed (Mazzotti et al, 2007). Endotoxin is released into the environment during bacterial cell death or cell division occurs. Endotoxin is known as a potent inflammatory…show more content… Then the blower was turned on for sufficient duration and UV lights were switched on for one hour. LAF microbial contamination test (Settling plate method)
A total of three petri dishes were prepared aseptically inside a laminar air flow (LAF), and then the petri dish was filled by pouring sterile Tryptone Soy Agar (TSA) liquid media and allowed to solidify. One test media was placed in the LAF cabinet, one test media is placed beside the LAF cabinet while the other the test media was placed near the door. The three petri dishes lid were opened and allowed to stand for 15 minutes and closed again. Then, the test media is then incubated at 37 ° C, for 18-24 hours.
Rinsing reusable instruments
The samples were rinsed with 40 ml of pyrogen-free water using a glass beaker that is free from pyrogens.
Endotoxin testing using STV
A total of 0,2mL from the water obtained from the rinsing was placed in the STV containing LAL reagent and was shaken for 20 to 30 seconds. Then STV was placed in an incubator at 37 ° C for 60 ± 2 minutes. STV was then observed by reversing the reaction tube in one smooth motion. Negative controls performed using pyrogen-free water that is poured into a glass beaker which has been…show more content… This is shown by the negative result by the absence of microbial growth on the growth media Tryptic Soy Agar (TSA), the LAF cabinet meets the requirements according to Good Manufacturing Practice (GMP) sterile room, where the number of bacteria colonies in the LAF cabinet must be below 1 cfu/m3 which is a requirement for a class A area (C.Pasquarella, O.Pitzurra, & A.Savino, 2000).
The LAF area is a class I area or it is also known as a white area. This area must fulfill the requirements regarding the amount of microbes and particles. LAF room equipped with a hepafilter that filters the air flowing in the cabinet, the air movement in the LAF cabinet is laminar so that the microbes as well as particle from outside the room cannot enter into the area (Rees, Smith, & Watson, 2014).
Results of rinsed reused sterile medical instruments.
As much as 40ml of pyrogen free water used to rinse the reusable medical instruments, the amount of pyrogen free water which was used is done in accordance with the formula for endotoxin limits on rinsing. The formula which is used is as below (USP,