Everything in your inventory is one of three kinds. They share the same basics and differ in the extra detail each one needs. Picking the right kind up front saves you from an inventory where half the entries cannot answer the question you are asking. All three live in one inventory rather than three separate systems.
The quick answer
| If it is... | Use |
|---|---|
| A chemical or biological reagent you bought, that arrives in batches | Reagent |
| A consumable you buy in bulk and just run down | Supply |
| Material your lab collected or produced | Sample |
Rule of thumb: if the lot number matters, it is a reagent. If you only care how many are left, it is a supply. If your lab made it or collected it, it is a sample.
What they share
All three have a name, a quantity and unit, and a storage location. All three appear on the Inventory page, can be moved between locations, and have their changes recorded in the Audit Log.
How they differ
| Reagent | Supply | Sample | |
|---|---|---|---|
| Lot tracking | Yes, lots are a first-class thing | No | No |
| Hazard level | Yes, required | No | No |
| CAS number | Yes, optional | No | No |
| Expiration date | Yes, required per lot | No | No |
| Vendor | Yes | Yes | No |
| Reorder threshold | Low Stock Threshold, on the reagent | Reorder threshold, on the supply | No |
| Sterile / RNase-free | Yes | Yes | No |
| Collection date | No | No | Yes, required |
| Sample type | No | No | Yes, optional |
| Biohazard flag | No | No | Yes |
| Thaw state | No | No | Yes |
| Consumption action | Pull a portion | Use supply | Pull a portion |
| Plan needed | Any | Any | Lab |
Reagents in more detail
A reagent is recorded in three layers, which is why its add flow has three steps:
- The reagent on your master list: the substance, its default unit, its hazard level.
- A lot: the batch you received, with its lot number, vendor, and expiration date.
- An inventory item: the actual container on the shelf, with its quantity, location, and owner.
That structure is what lets you answer "which lot was in that experiment" months later. It is also why adding a reagent asks more of you than adding a supply.
See Add a reagent.
Supplies in more detail
A supply is one running total. There is no batch layer, because for a box of tips nobody needs to know which shipment it came from. What you do want is to be warned before you run out, which is what the reorder threshold is for.
When you use some, you record the amount with Use supply, and the item closes itself at zero.
See Add a supply.
Samples in more detail
A sample is material your lab is responsible for. The extra fields are all about the physical specimen: when it was collected, whether it is a biohazard, and whether it is still frozen. A sample can also be derived from another item, which keeps the link back to what it came from.
See Add a sample and Samples: collection, thawing and biohazard.
What if I picked the wrong one?
There is no convert action. If you recorded something as the wrong kind, add it again as the right kind and close the original. See Update, consume, or adjust an item's quantity for closing an item.
Worth getting right the first time on anything you will need lot history for, since a supply record cannot grow lots later.
Made in-house, not bought
If your lab prepares a reagent from a recipe rather than buying it, that is still a reagent, but there is a dedicated flow for creating a fresh batch of it that draws down the inputs at the same time. See Make a reagent from a recipe.