BOSTON — One of the two laboratories licensed to test marijuana that will be sold in Massachusetts said it’s turning around samples in a timely manner and is not contributing to a shortage of flower at some retail marijuana stores.

Last week, New England Treatment Access stores in Brookline and Northampton had a limited supply of marijuana buds for recreational customers and posted notices to their menus explaining the dry period was due to a backlog at the testing labs. Though other retailers may have experienced similar issues, NETA took the step of making customers aware.

“Our flower test results have been significantly delayed as the state’s labs work through a testing backlog,” the company wrote below the flower section of each menu. “We are doing everything we can to work with our regulators and laboratory partners to get things back on track.”

MCR Laboratories, a Framingham lab that analyzes samples of marijuana for companies around the state, said that it has been churning through its samples at its usual pace.

“We currently have no backlog of test samples and are providing results to clients within our standard 2 to 5 business day turnaround time,” MCR Labs’ Joe Crinkley told State House News Service in an email. “This timeline accounts for the time it takes for us to prep samples, run the requested analyses, and generate the certificate of analysis (COA) that is then sent back to clients.”

CDX Analytics of Salem, the second of two licensed independent testing labs, did not respond to inquiries from the News Service.

As of Monday morning, NETA had five strains of flower available on its Northampton menu (with three noted as being in limited supply) and four strains of flower posted on its Brookline menu (with two noted as limited supply).

No marijuana, medical or recreational, may be sold in Massachusetts until it is tested and approved for sale by an independent testing laboratory. The Cannabis Control Commission has licensed two labs to conduct the testing for the 28 non-medical retailers it has allowed to open across Massachusetts.

The CCC guidance for retailers and dispensaries around testing requires that a sample from strain-specific 10-pound packages be tested by an independent lab before it can be sold. All marijuana must be tracked from seed to sale in the CCC’s Metrc system.

The CCC has also issued a provisional license for a third testing lab, Evio Labs of Framingham, and CCC staff is still reviewing three other testing lab applications. A CCC spokesperson said last week that those applications may not yet be ready for a vote of the commission.