OT:RR:NC:N3:138
Susie Hoeger
Abbott
100 Abbott Park Road, D-03CC, AP6D-2
Abbott Park, IL 60031
RE: The country of origin of monoclonal antibodies
Dear Ms. Hoeger:
In your letter dated January 9, 2026, you requested a country of origin ruling on monoclonal antibodies. We
apologize for the delay as the information was submitted to our laboratory for analysis.
You stated that Abbott imports monoclonal antibodies that are used in toxicology tests to detect drugs of
abuse in patient samples. The monoclonal antibodies are produced via two different scientific methods as
follows:
1) Hybridoma cell technology
2) Chinese Hamster Ovary (CHO) cell culture medium
The hybridoma cell technology method is a three-step production process that includes cell line creation,
antibody production and purification. The first step is the creation of the hybridoma cell line in China where
the hybridoma cell line is generated by fusing an antibody-producing B lymphocyte with an immortal
myeloma cell. The hybridoma cell line is then cryopreserved in aliquoted vials and stored under liquid
nitrogen. The second step involves the antibody production of the monoclonal antibodies that occurs in China
or Finland. During this step, the cryopreserved hybridoma cells are thawed and injected into the peritoneal
cavity of mice to produce ascites. The hybridoma cells proliferate in vivo and secrete monoclonal antibodies
into the ascitic fluid. The ascites fluid is then harvested from the mice, pooled, and frozen for subsequent
purification. The third step involves purification of the monoclonal antibodies in China or Finland. The
antibodies are purified using Protein A chromatography, formulated into a buffer solution, filled into
polypropylene containers, and shipped frozen to the United States.
The CHO cell culture medium method is also a three-step production process that includes cell line creation,
antibody production and purification. The first step is the creation of the CHO cells in China where the CHO
cells are genetically engineered to express a specific monoclonal antibody. The CHO cell line is then
cryopreserved in aliquoted vials and stored under cryogenic conditions. The second step involves the
antibody production of the monoclonal antibodies that occurs in China or Finland. During this step, frozen
CHO cells are thawed and inoculated into culture media in shaking flasks. Nutrients are supplied through a
fed-batch process to extend cell viability and antibody productivity. After approximately 14 days, the culture
is harvested and clarified by centrifugation to remove cells and debris, yielding antibody containing culture
supernatant. The third step involves purification of the monoclonal antibodies in China or Finland.
Monoclonal antibodies are purified from the clarified culture supernatant using Protein A affinity
chromatography, formulated into a buffer solution, filled into polypropylene containers and shipped frozen to
the United States.
When determining the country of origin, the substantial transformation analysis is applicable. See, e.g.,
Headquarters Ruling Letter (“HQ”) H301619, dated November 6, 2018. The test for determining whether a
substantial transformation will occur is whether an article emerges from a process with a new name,
character, or use different from that possessed by the article prior to processing. See Texas Instruments Inc. v.
United States, 681 F.2d 778 (C.C.P.A. 1982). This determination is based on the totality of the evidence. See
National Hand Tool Corp. v. United States, 16 C.I.T. 308 (1992), aff’d, 989 F.2d 1201 (Fed. Cir. 1993).
In this case, the country of origin of the monoclonal antibodies will be China or Finland, where the
monoclonal antibodies are produced during the antibody production stage.
The holding set forth above applies only to the specific factual situation and merchandise description as
identified in the ruling request. This position is clearly set forth in Title 19, Code of Federal Regulations
(CFR), Section 177.9(b)(1). This section states that a ruling letter is issued on the assumption that all of the
information furnished in the ruling letter, whether directly, by reference, or by implication, is accurate and
complete in every material respect. In the event that the facts are modified in any way, or if the goods do not
conform to these facts at time of importation, you should bring this to the attention of U.S. Customs and
Border Protection (CBP) and submit a request for a new ruling in accordance with 19 CFR 177.2.
Additionally, we note that the material facts described in the foregoing ruling may be subject to periodic
verification by CBP.
This ruling is being issued under the provisions of Part 177 of the Customs and Border Protection
Regulations (19 C.F.R. 177).
A copy of the ruling or the control number indicated above should be provided with the entry documents
filed at the time this merchandise is imported. If you have any questions regarding the ruling, please contact
National Import Specialist Judy Lee at [email protected].
Sincerely,
(for)
James P. Forkan
Director
National Commodity Specialist Division