Meristemic propagation of plants Institute.

The active ingredients are 5-chloro-2-methyl3(2H)-isothiazolone and 2-methyl-3(2H)- isothiazolone. That is why for callus in vitro culture in labs the PPM is effective against bacteria and fungi, is heat stable, and can be autoclaved. You only use some microliters per callus stem in your laboratory.

Genprice's shipping of the Plant Preservative Mixture (PPM) exceeded my expectations. The package arrived promptly and was securely packaged to prevent any damage during transit. Overall, I am highly satisfied with the shipping service provided by Genprice and would not hesitate to recommend them to others seeking reliable and efficient shipping for their products.

War am nächsten Tag in Skopje, Macedonia.

The PPM does not inhibit the in vitro seed germination or the good callus proliferation and callus regeneration. PPM prevents the germination of both bacteria and fungi spores.

We bought PPM PLANT PRESERVATIVE MIXTURE from Gentaur Maxanim the distributor of Plant Cell Technology, Inc. in Europe. They told us that Plant Cell Technology has developed this heat stable preservative biocide, to eliminate all microbial contamination in plant tissue culture. It is indead an very effective plant medium decontaminantion agent but it does not impair in vitro seed germination, callus proliferation and callus regeneration. So despite the most stringent use of sterile techniques, the contamination of plant cell and plant tissue cultures remained a persistent problem for us that resulted always in losses ranging from small number of cultures to the loss of whole batches. Thanks to PPM we could prevent the germination of both bacteria and fungi spores. It is heat stable and therefore we could autoclaved it with the PPM. Our plant tissue culture mediais now expensive than the harmful antibiotics we used before! So PPM is designed to inhibit airborne contamination, waterborne contamination and contamination introduced from human contact, but for us it reduces endogenous internal contamination. PPM tissue culture protocol we use: 1. Media containing PPM can be dispensed outside the laminar flow hood (LFH) exposed to the ambient air. The plates should be covered soon after agar solidification. In the event that media dispensing is done by a pump, we recommend passing autoclaved hot water through the hoses prior to and after media dispensing. 2. Heat sensitive or heat stable liquid media containing PPM does not need to be sterilized by Millipore filters or autoclaved provided that it will be stored in sterile containers and that the stock solutions are not contaminated. In rich media containing 200 mg/liter or more of amino acids or proteins, it is recommended to filter the media with the PPM. 3. If working in the LFH the utensils (forceps or scalpels) do not need to be flamed. They should be periodically dipped in 70% alcohol. The LFH does not need to be certified and the work can be done as well outside the LFH on a clean surface for a period not exceeding 1 hour. 4. PPM™ is an acidic liquid solution (pH 3.8). PPM™ should be stored at 4°C. (see Safety Information below). The recommended dose is 0.5 – 2.0 ml of PPM™ per liter of medium is added to the medium before or after autoclavation to prevent airborne and endogenous contamination at low inoculum densities. Higher doses are required to treat endogenous contamination or to obtain Agrobacteria free plant material. 5. PPM™ is less effective when exposed to high density of bacteria or fungi spores found on seed’s coat. For in vitro germination, seeds should be conventionally surface sterilized with bleach. Therefore, in the presence of PPM™ (in the germination medium), the seeds can be rinsed under tap water in a non-sterile strainer and left to dry preferably in the LFH. If the utensil ends have touched active bacteria, fungi culture or otherwise suspected of being contaminated, they should be sterilized by autoclaving or by use of an electric heating element. 6. General dosage levels. With the exception of endogenous contamination, the recommended dose range is 0,05% – 0,2%. For callus proliferation, organogenesis and embryogenesis, the recommended range is 0,05%- 0,075%. Add PPM™ to medium pre or post autoclavation to prevent airborne contamination and endogenous contamination at low inoculum densities or slow growing bacteria. To eliminate higher endogenous contamination densities, higher doses of PPM™ are needed (see paragraph 7). 7. Endogenous Contamination: (a) For seeds: stir non-sterilized seeds for 8-12 hours in 2% PPM™ solution (v/v) supplemented with full strength basal salts of your routinely used medium and don’t add Tween 20 or pH this solution. Subsequently, without rinsing, transfer to germination medium supplemented with 0,05% – 0,1% PPM™ for herbaceous plants and 0,2% PPM™ for woody plants. Hard coated seeds such as Asparagus, Lupine, Ornamental Palm, Rose etc. should be soaked in water for 2-4 hours prior to the sterilization with PPM. (b) For explants: gently shake / stir 1 cm long explants (or shorter) routinely in bleach solution to remove surface contamination. Rinse with water (can be done under non sterile conditions) and shake / stir for 12 hours in 4-5% v/v PPM™ solution supplemented as above with full MS (or 2X) strength basal salts without pH ing and without Tween 20. Without rinsing, insert into a medium supplemented with 0,05% – 0,1% PPM™ for herbaceous plants and 0,2% for woody plants If possible, collect woody plant material after dormancy is broken. This will substantially decrease contamination. (c) For tubers: shake /stir the entire tuber routinely in bleach solution. Rinse with water (can be done under non sterile conditions) and slice the tuber (bulb or scale) into thin slices. Shake / stir for 12 – 24 hours in 4-5% PPM™ solution supplemented with full strength (or 2X) basal salts without pH ing and add Tween 20. Without rinsing insert into a medium supplemented with 0,1-0,2% PPM™. 8. In cases that the above protocols don’t yield satisfied results (especially with thick explants or highly infested explants and seeds), we recommend the followings: (a) Shake / stir the explants (or seeds) in water (does not have to be sterile), 1 hour for soft tissues and 2 hours for hard tissues (b) Shake / stir the explants in 50% PPM™ (dilute with sterile water) supplemented with 2X full strength MS basal salts without pH ing and Tween 20 for 10 – 15 minutes. (c) Without rinsing, insert the explants in to the medium. In fungal contamination, the addition of PPM™ to the medium is optional. However in bacterial contamination or mixed contamination, the addition of 0,05-0,2% PPM™ to the medium in the first month is essential. Don’t discard highly oxidized explants, approximately 50% will recover after 4-6 weeks. 9. To decontaminate “in culture” contaminated explants or plants (rescue treatment), the cultures shouldn’t be left visibly contaminated longer than one week. Clean the material mechanically with the aid of a soft brush under stream of tap water. Shale / stir in a 50% PPM™ solution (diluted with sterile water) for 5 – 15 minutes. In bacterial contamination or mixed contamination, we recommend to lower the pH to the range of 2.8 – 3.2 by mixing 1:1 full strength 100%PPM™ with 0,6 g/l citric acid solution (use sterile water). Without rinsing insert into a medium with 0,05-0,2% PPM™ for at least one month and keep the culture away from high light intensities for the first 10 days. As mentioned above, don’t discard oxidized explants. Wait 4 – 6 weeks. In some cases the fungal or the bacterial spores are located deep within the explants beyond PPM™ reach. In those cases after the water soaking period, slice the explants along and then stir / shake in 50% PPM™ for 10 – 15 minutes.