Plant Preservative Mixture (PPM)

Controller of microbial airborne contamination. Manager of microbial waterborne contamination. Inhibitor of endogenous contamination. Enhancer of the success of culture experiments. Maintainer of the viability of in vitro seed germination. Promoter of callus proliferation. Supporter of callus regeneration. Ensurer of the stability of tissue culture media.

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%.) To eliminate higher endogenous contamination densities, higher doses of PPM™ are needed. Endogenous Contamination: (a) For explants: gently and routinely shake / stir 1 cm. long explants (or shorter) for 4-12 hours in 4-5% v/v PPM™ solution supplemented as above with 3x MS strength basal salts without Tween 20.Without rinsing, insert into a medium supplemented with 0.05 - 0.1% PPM™ for herbaceous plants and 0.2% PPM™ for woody plants. Note: Paragraphs 6(b) through 10 below are intended for ornamental plants only. (b)For tubers, bulbs and scales: shake / stir the entire tuber/ bulb / scale in bleach. Rinse with water (can be done under non-sterile conditions). Slice the tuber / bulb /scale to thin slices. Shake / stir for 12-24 hours in 4- 5% PPM™ solution supplemented with full strength basal salts without pH ing & Tween 20. Without rinsing, insert into a medium supplemented with 0.1 -0.2% PPM™.

At optimum doses, PPM™, which stands for Plant Preservative Mixture™, is an extremely effective Preservative/Biocide, yet does not impair in vitro seed germination, callus proliferation and callus regeneration. PPM™ prevents the germination of both bacteria and fungi spores. It is heat stable and therefore can be autoclaved with the media. PPM™ can be, and should be used as a standard ingredient in plant tissue culture media, and is also substantially less expensive than commonly used antibiotics. While PPM™ was principally designed to inhibit airborne contamination, waterborne contamination, and contamination introduced from human contact, it can also, in many cases, be used to reduce endogenous contamination. PPM™ does not affect the genetic profile of the plants.