After collection of benthic samples for meiofauna, from intertidal and subtidal regions, What is the best applicable method for storing the processed samples, which will be later processed using Ludox. I mean which is best preservative , 70% ethanol or 5% buffered formaldehyde
Thank you all in advance
Hello Dr. Gopikrishna Mantha
A few taxa do better in ethanol but for most of the meiofauna samples buffered formalin tends to serve as the most common fixative/preservative. 4% buffered formalin (not formaldehyde) concentration is normally attained within the sample. Many other researchers have had success with using Bouin's fluid. Buffering should be done by either using Borax buffer tablets or combined Na2HPO4 and NaH2PO4 as phosphate buffers. BUT preserving marine or higher brackish water samples tend to cause precipitates in phosphate buffers.
Soft bodied species may be best anaesthetised first to relax their muscles prior to preservation using hydrated MgCl2. Ethanol dissolved Menthol can also be used as the muscle relaxant in soft bodied taxa. A far better fixative than formaldehyde (or formalin, as solution) is gluteraldehyde but its rather costly and more carcinogenic.
In my view, the two very best agents to serve as fixatives or preservatives of meiofaunal samples are Trump's solution (containing Na cacodylate) and Sodium Cacodylate buffer as none of these suffer from pH shifts nor sample degradation due to microbial contamination. Microwave fixation followed by optimisation with formalin or ethanol is also another viable option for long term fixation in addition to the widely successful shock freezing method using liquid nitrogen.
I personally have used formalin, ethanol, and Na-Caodylate buffer, the latter with better long term reliability.
I sincerely believe this should enable you to select the best one according to your need.
Regards,
Dr. Abhishek Mukherjee
Please consult " Marine invertebrate sample processing procedures by Robin Wilson Museum Victoria [email protected] "
Fantastic explanation has been highlighted by Dr Abhishek Mukherjee. I like to extend my appreciation to him.
Good day
Thank you very much Dr. Abhishek Mukherjee for your clarification.
& Also thanks to Dr. Abhijit Mitra for his information given
Thanking you all with regards
Dr. Gopi
