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Cytogenetics

Monitor Supplies & Chemicals

Running a cytogenetics laboratory requires the continuous availability of specialized consumables and short-shelf-life reagents. A “stock-out” of a critical item like Fetal Bovine Serum (FBS) or culture flasks can halt patient testing entirely. Therefore, robust Inventory Management and Chemical Hygiene plans are essential operational components

Inventory Management Strategy

  • Critical vs. Non-Critical Items
    • Critical: Items that directly affect the test result and have no immediate substitute (e.g., FBS, Phytohemagglutinin (PHA), FISH probes). These require stricter monitoring and “safety stock.”
    • Non-Critical: General supplies (e.g., paper towels, gloves, Kimwipes)
  • The “Kanban” or Tag System
    • A physical tag or card is placed at the “reorder point” in the stock (e.g., when 5 bottles of media remain). When the user grabs the bottle with the tag, they hand the tag to the ordering manager. This triggers the re-order
  • First-In, First-Out (FIFO)
    • New supplies are placed behind old supplies. This prevents reagents from expiring on the shelf
  • Lot Sequestration
    • For biologically sensitive reagents (FBS, Media), labs often “sequester” (reserve) a large amount of a specific Lot Number: from the manufacturer after it passes Quality Control testing. This ensures consistency for 6–12 months. Changing lots frequently introduces variables that can cause culture failure

Chemical Monitoring & Safety (OSHA)

Cytogenetics uses several hazardous chemicals (Fixatives, Stains, Mitogens)

  • Chemical Inventory List
    • A master list of every chemical present in the lab must be maintained and updated annually
    • This list is cross-referenced with the Safety Data Sheets (SDS): library
  • Expiration Tracking
    • Received Date: Written on the bottle when it arrives
    • Opened Date: Written when the seal is broken
    • Expiration Date: The manufacturer’s date is often valid only until opened. Once opened, internal stability rules apply (e.g., “Giemsa stain expires 30 days after opening”)
    • Disposal: Expired chemicals must be removed from the bench. Using expired reagents is a major deficiency in inspections
  • Spill Kits
    • Specific neutralization kits must be available for the main hazards: Acid Spill Kit (for Acetic Acid) and Solvent Spill Kit (for Methanol/Xylene)

Lot-to-Lot Quality Control (QC)

Before a new shipment of supplies is released for use, it must be verified

  • Reagents (Media/Serum)
    • Tested on a “control” culture (e.g., a normal blood sample)
    • Criteria: Does it support growth? Is the Mitotic Index comparable to the old lot? Is the morphology good?
  • Physical Supplies (Slides/Flasks)
    • Sometimes a new lot of microscope slides has a different surface charge (hydrophobicity) that ruins chromosome spreading. New lots of slides are “test dropped” before being put into routine circulation

Controlled Substances

Some chemicals require strict legal tracking

  • Ethanol: Pure (200 proof) ethanol is tax-free for clinical use but strictly regulated. Usage logs must track every milliliter dispensed to prevent diversion
  • Poisons: Highly toxic agents (e.g., Colchicine powder, Ethidium Bromide) should be stored in locked cabinets

Waste Management

Monitoring supplies also means monitoring their disposal

  • Segregation
    • Biohazard (Red Bag): Items contaminated with blood/cells (Gloves, Flasks)
    • Chemical Waste: Methanol/Acetic acid fixative cannot go down the drain. It is collected in satellite accumulation drums for hazardous waste pickup
    • Sharps: Needles and broken slides
    • PII: Paperwork with patient names must be shredded