How to Choose a Radiocarbon Dating Laboratory and Submit Samples

Updated

Choose a radiocarbon dating laboratory by matching three things to your project: the dating method (AMS vs. radiometric), the turnaround time you can accept, and the sample types the lab will pretreat and run. SGS Beta Carbon Dating Service, for example, states that it provides AMS dating results in 3–14 business days and also offers stable isotope analysis — a useful benchmark when you compare other labs. Before you ship anything, confirm the lab accepts your material, ask what pretreatment is included, and check the published closure schedule, because holiday shutdowns can add weeks to your result date.

Compare labs on the dimensions that change your result

Method, turnaround, and sample size are linked. AMS (accelerator mass spectrometry) counts carbon-14 atoms directly and needs far less material than radiometric dating, which counts decay events over a longer period. If your sample is small, precious, or you need an answer quickly, AMS is usually the deciding factor. If you have a large, robust sample and no deadline pressure, radiometric counting may be offered as an alternative — but confirm the lab still runs it, since many facilities have consolidated onto AMS.

Dimension What to ask Why it matters
Method AMS or radiometric? Determines minimum sample size and typical turnaround
Turnaround Standard vs. rush, in business days SGS Beta advertises 3–14 business days for AMS
Sample size Minimum grams/ milligrams per material Too little material means rejection or a re-run
Pretreatment Included or extra? Removes contaminants that skew the age
Reporting Calibration, error range, delta-13C Needed to interpret and publish the date
Schedule Holiday/lab closures A closure can push your result past your deadline

Check accepted sample types and pretreatment

Labs publish the materials they routinely handle. The SGS Beta page lists technical support for selecting suitable samples and names Bones & Teeth, Shell & other Carbonates, Plants & Seeds, and Wood among its categories. Use that list as a checklist against your own material:

  • Bone and teeth — usually need collagen extraction; ask whether the lab reports collagen yield, since low yield signals a unreliable date.
  • Shell and other carbonates — sensitive to recrystallization; ask about acid pretreatment and whether the lab checks for secondary carbonate.
  • Plants, seeds, and charcoal — often the cleanest material; confirm whether the lab picks out rootlets or other intrusions.
  • Wood — ask whether the lab can date a single growth ring or must run a bulk sample, since that affects precision.

If your material is not on the lab's published list, email a description and photo before shipping. A lab that has not pretreated your sample type before may still accept it, but you want that confirmed in writing.

Understand what drives the price before you request a quote

Pricing is quoted per project, not published as a flat rate on the page reviewed here. The factors that typically move a quote:

  1. Number of samples — per-sample cost usually drops with batch size.
  2. Pretreatment — collagen extraction, carbonate leaching, or specific chemical washes are often billed separately from the measurement.
  3. Rush service — expedited turnaround carries a premium.
  4. Re-runs — if a sample fails or is contaminated, you may pay again; ask about the lab's policy.

Request a written quote that itemizes measurement, pretreatment, and any rush fee, and ask what happens if the sample yields no result.

Prepare and label samples to avoid rejection

Most bad outcomes trace back to contamination or mislabeling, not to the measurement itself.

  • Do not touch the sample with bare hands; skin oils add modern carbon.
  • Use clean packaging — foil, glass, or lab-supplied vials. Avoid paper and cotton, which can transfer carbon.
  • Label inside and outside the container with a unique ID, and keep a matching list of what each ID is, where it came from, and its depth/context.
  • Dry samples if the lab requests it, and note any preservative or treatment already applied.
  • Ship with the lab's required forms so the sample is logged on arrival.

Confirm reporting and schedule before you ship

Ask what the final report includes: the conventional radiocarbon age, the calibrated date range, the delta-13C value, and the error margin. Calibration matters because the raw radiocarbon age must be converted to a calendar date using a calibration curve, and the curve you use depends on the material and region.

Then check the calendar. The SGS Beta page publishes a 2026 closure schedule: November 19, November 26–27 (Thanksgiving), and December 24, 2026 through January 1, 2027 inclusive for Christmas and New Year. If your deadline falls near those dates, either ship well ahead or confirm the lab's cutoff for samples received before the closure. A sample that arrives the day before a shutdown may not be logged until the lab reopens, adding the full closure period to your turnaround.

A practical submission sequence

  1. Identify your sample material and estimate its size.
  2. Shortlist two or three labs that accept that material and offer AMS.
  3. Request quotes with pretreatment and rush options itemized.
  4. Compare turnaround against your deadline, including published closures.
  5. Confirm reporting format and calibration.
  6. Package, label, and ship with the required forms.
  7. Track receipt and confirm the expected result date in writing.

If a lab cannot confirm pretreatment for your material, cannot give a written turnaround, or will not state what the report contains, that is a reason to look elsewhere — regardless of price.