Lab Procedures and Protocols

Lab Management and Safety Concerns

• Outdated Chemicals:

  • Mention of having outdated chemicals in the lab, specifically sodium chloride.

  • Question raised: How does sodium chloride become out of date?

  • Instruction to seek guidance on handling this issue.

• Cluttered Shelves:

  • Noted concern that some shelves in the lab were overburdened or cluttered.

  • Observation that the lab appears cleaner compared to other work areas.

  • Need for guidance on addressing shelf organization and clutter.

Plant Care Procedures

• Rinsing Plants:

  • Planned activity to retrieve plants from the window for rinsing.

  • Rinsing to be done thoroughly; previous experience suggests a minimum of two containers of water may be required.

  • Background: Previous batch had smaller root systems, the current batch is over a month old and has larger roots.

• Rinsing Methodology:

  • Use of multiple bins for rinsing plants:

  1. First Bin:

     • Used for gently removing soil from the plant roots.

     • Plant taken out of its container and excess soil knocked off.

  2. Second and Third Bins:

     • Filled with water to cleanse residual soil.

     • By the third container, roots should be mostly clean.

• Root Systems Assessment:

  • Discussion on the potential complexity of the root systems being examined.

  • Potential to identify lateral roots and root distribution.

  • Notes that measurement of root systems may not be practical due to their size (e.g., a plant might have around 200 roots).

Experimental Setup for Roots

• Chopping Roots and Shoots:

  • Previous method involved cutting half a centimeter from the base of the stem for preparation.

  • Determined the base of the stem by observing the thickest part just before it begins branching.

  • Intention to apply the same cutting rule for the current batch.

• Weight Measurement:

  • Plan to measure root weight and shoot weight after plants dry.

  • Roots will be stored in labeled tubes with water.

• Tubes for Samples:

  • Need to ensure 24 tubes are available for the experiment.

  • Previous discussions confirmed the existence of some tubes, but total count remains uncertain.

Experiment Focus and Mycorrhizae Investigation

• Mycorrhizal Fungi Focus:

  • Current experiment aims to observe differences in powdered fungi behavior and its impact on root and shoot weights.

  • Decision to save some unlabeled tubes in case they are needed based on experimental outcomes.

• Expected Outcomes Analysis:

  • Statistical analysis planned to measure root and shoot weight differences.

  • If results show no significant differences, the application of mycorrhizae may not be pursued further.

• Previous Experiments with Microbial Infections:

  • Personal experience noted with pulling plants at various intervals (5 days vs. 7-10 days) showing varying levels of microbial infection presence.

  • Noted variability in infection rates depending on the timing of observations and extraction methods.

Measurement Techniques and Statistics

• Measurement Challenges:

  • Discusses the statistical insignificance of measuring root mass, length, and size due to variability among plants (e.g., large number of small roots vs. single long root).

  • Suggestion to potentially measure root ball size, root ball diameter, or the overall root system diversity.

• Importance of Replicability:

  • Emphasis on the need for measurements to be replicable for adequate scientific proof; non-replicable observations are deemed less valuable in research.

Safety and Cleanliness Protocol

• Handling Waste Water Practice:

  • Safety reminder: If dirty water buckets are dumped, the waste must be passed through a sieve to prevent clogging in drains.

  • Any root material that detaches while rinsing must be gathered and recorded for weighing.

• Root System Observation:

  • Plan in place to potentially perform mycorrhizal staining to ascertain infection levels among root systems, pending time availability.

Nutrient Management for Healthy Growth

• Fertilization Strategy:

  • Intent to mix a light dose of fertilizer to maintain plant health without overwhelming the mycorrhizal fungi and beneficial PGPR (Plant Growth-Promoting Rhizobacteria).

  • Discussion regarding balancing nutrition to ensure plants remain healthy while supporting mycorrhizal interactions.

Other Laboratory Activities

• Preparation for Plate Inspection:

  • Plan noted to check on the prepared petri plates to observe and compare microbial colonies.

  • Importance of ensuring consistency in colony size across sample plates for valid comparison.

• Lane Protocol for Plates:

  • Ensure group alignment for identical observation outcomes and proper handling procedures.