Sample and Inventory Management
TL;DR
Lab inventory management is keeping track of the reagents, consumables, samples and equipment a lab holds: what each item is, where it sits, how much is left and which experiments used it. In software, it replaces the freezer-door sheet and the shared spreadsheet with linked records that show who changed what, and when.
Lab inventory management is the practice of keeping an accurate, current record of everything a lab holds and uses, from antibodies and kits to cell lines, plasmids and plastics. For any item, a useful inventory tells you what it is, where it is, how much is left and what it has been used for.
Most labs start with a spreadsheet on the shared drive and a paper sheet taped to each freezer door. That holds up while the collection is modest and one person looks after it. It gets harder once more people share the same boxes, since every withdrawal is a separate edit and the sheet keeps no history of who changed what.
The term overlaps with laboratory information management system (LIMS), and people use the two loosely. Inventory management is the activity. A LIMS is one type of software that does it, usually with sample relationships and audit trails on top. Purchasing and ERP systems are different again: they track orders and invoices, but not which tube went into which experiment.
Picture a Friday evening search of a -80 °C freezer for one specific vial. With a current inventory it is a lookup and then one rack pulled. Without one, the door stays open for ten minutes while everyone else's samples warm up.
The lookup depends on how the record is built. Each item gets a unique ID and a label when it enters the lab, with the lot number recorded for reagents, because the lot is what matters when a kit misbehaves. Storage is recorded as a nested hierarchy of room, freezer, rack or shelf, box and position, so the record points at one slot in one box. And usage is logged at the point of use. Take 50 µL from a 500 µL antibody aliquot and the record drops to 450 µL, with your name and the experiment attached.
Quantity is the Monday half of the question. Finding out at 9 AM that the last tube of competent cells went on Thursday costs a day, or a week if the cells have to be ordered or made. So for the items that matter, a low-stock notice goes to whoever orders or prepares more while there is still an aliquot or two left.
Linking items to experiments is what turns a stock list into traceability. When a result won't reproduce, the first questions are about materials: same antibody lot, same serum lot, same passage, same buffer prep? If a lot of competent cells turns out to have low transformation efficiency, the lab can pull up every cloning experiment that used it. The post on solving common lab inventory problems goes through more of these situations.
For studies conducted under GLP, documenting the identity and handling of test items and reagents is a regulatory requirement, and the inventory record becomes part of the study record. Outside GLP, the same records make methods sections and collaborators' data requests much quicker to answer.
Whichever one costs the lab the most time. For many labs that is a shared -80 °C freezer or the antibody collection, and the plastics can wait. Inventory that one unit completely, box by box, labeling as you go. A complete record of one freezer is more useful than a partial record of everything.
Agree on the fields before loading any data. Item type, lot number, concentration, owner and storage position cover most needs. Then decide which items get quantity tracking: a running total makes sense for antibodies and expensive kits, and for pipette tips it is overhead.
Set notify levels with the people who make or order the replacements. Base each one on lead time, so an antibody with a two-week delivery gets a higher level than a buffer someone can make up in an afternoon.
IGOR tracks inventory in the same platform as its electronic lab notebook, in the Inventory (LIMS) module. Storage locations are set up as a nested hierarchy of Facility, Site, Equipment and Location, and Box Map View shows each box as a grid with every position color-coded by sample status. Quantity tracking is optional per item. An item at or below its notify threshold appears on the Inventory Alerts tab in Mission Control, and crossing the threshold emails the people named on it.
Inventory software that records storage locations and keeps a timestamped history of every change is the usual replacement. Look for barcode scanning, bulk upload from your existing spreadsheet, quantity tracking for expensive reagents, and links between items and the experiments that used them. Then move one freezer at a time, so each part is complete before people rely on it.
Record the lot number as a field when the reagent arrives, and link the item to each experiment that uses it. Each new lot should be its own inventory item, not an edit to the old one. Then when a lot is recalled or behaves oddly, you can list every experiment that used it.
Give each tracked item a threshold quantity and name the person to tell when stock reaches it. Set the threshold high enough to cover the time it takes to order or prepare more. In IGOR, an item crossing its notify threshold emails the people named on it.
Yes, in most research labs, kept in separate repositories with their own fields. Samples and reagents share freezer space and both go into experiments, so one system shows the full set of materials behind a result. A cell line still needs a passage number, and a reagent needs a lot number.
Many labs count high-value items every few months and check each freezer fully once a year. A count catches drift between the record and the shelf, like an empty tube still sitting in its box. Record the corrected amount with a reason, so the history shows a recount and not an unexplained change.