An Introduction to Petri Dish Preparation for Use With Growth Medium - Day Two (P1/4 in a Two-Blog Series)

in STEMGeeks3 months ago (edited)


And hopefully I can help educate yourself on some information I will be examining regarding preparation and use of plastic or glass petri dishes for bacterial and psilocybin mycelial examination. Without further adeu,

An Introduction - Petri Dish Prep: Cleaning, Sanitizing, Sterilizing, and to Re-Use or Not

Picking up from where we last left off: , introduced prior,
it is important to remember that while most petri dishes come prepared for bacterial work, it is always a good standard to follow disinfection procedures when working with new dishes.

One may think they can reuse contaminated plastic dishes, if proper chlorine bleach soaking and disinfection is completed prior this is very slightly plausible, but alas petri dishes are cheap and the resulting contamination that may occur is not worth the time nor effort. As seen below with a well-grown plastic petri dish growth with little to no contamination,


Comparitively to one that has been reused,


Signs of contamination are evident in multiple forms.

Cleaning, Sanitizing, then Sterilizing

Acquire one bowl for washing, one plastic container or small bucket for soaking, and a plastic container for sterilizing. In the first bowl, mix disinfecting soap and warm water to scrub the petri dishes. This is done with a soft non-abrasive cloth and toothbrush for approximately 30 seconds.
In the next, mix 1/8th cup of Clorox Bleach with 1 1/8th cups of warm water to soak the petri dishes. Lift the dish out of the soapy water and drop into the Clorox-water for two minutes.

In the last, pour 30-100mL of Isopropyl 90-99% Rubbing or Disinfectant Alcohol. With sterile tongs, transfer the dish from the Clorox-water after two minutes to the last container for 3 seconds and quickly lift out of the alcohol.

Place the dish face down in a plastic container with the top slightly open in a circulated room to dry condensation from the inside of the dish for two hours, then seal with parafilm or masking tape store for further use with Agar, to be explained next week here.

Before working with Agar, one should ensure decontamination of all surface surrounding is done. While air flow and circulation should already be consistent, one should disinfect the pouring table and anything surrounding thoroughly.

If not done, consistent transfers, or wedging -as previously examined on hypnochain- will have to be done, as seen in the below layout:


The individual should sanitize their self through shower and usage of lab coat or fresh, cling-free, non-shedding clothing. Safety glasses, hairnet, and latex or other gloves should be worn for the pouring of the dishes.

In the case that a Sealed Air Box – a closed top containment for contaminant free and still air transfer – is not available for use, high sanitary measures should be followed to reduce contamination risk of dishes during pouring, as this is increased tenfold without protection from air contamination.

Remember, the less air flow when working with the lid of a petri dish off when we pour Agar in the future for a medium such as so below, the better;


Hopefully this was an educational introductory read for anyone interested in preparation of petri dishes and the proper technique for cleaning.

The examination of liquid cultures from growth of mycelium on HypnoChaiin Monday is inspected here:. ,and the preparing for use of these dishes with will be examined at the end of the week on StemGeeks, here:

Yesterdays intro to growth can be found here:


Stemgeeks @

and the following week, the preparation of Agar Agar on StemGeeks (above), and mycelial utilization in liquids for culturing again on the HypnoChain blog (below),



As well as this following weeks posting on Liquid Culture:

Or here,

Hypnochain @

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Thanks again all for hopefully some potential interest, and look forward for more to come!

Best regards,

#mushroom #psilocybin #psilocybe #mycelium #mycelial #petri #spore #psychedelic #psychoactive #hypnotic #hive #ecency #hypnochain #stem #stemgeeks #proofofbrain

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