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Flow Cytometry FAQ's

Can you run flow cytometry from slides? On serum?

No, we cannot perform flow cytometry on slides, the cellular sample needs to be in solution. Serum is devoid of cells, so we cannot perform flow cytometry on serum. See the Flow Cytometry Submission Instructions.

How do I pack/ship samples to the lab?

  1. Send samples for flow cytometry overnight, on ice. DO NOT FREEZE! We do not recommend sending samples for flow cytometry for weekend delivery. We are open Monday through Friday, and the cell viability can decrease while the sample sits over the weekend.

  2. Samples for PARR testing do not need to be sent on ice, and can be sent standard mail or overnight, depending on how quickly you would like results.

  3. Specific instructions and shipping addresses can be found on the Shipping Instructions page.

What species can you test?

Canine and feline patients only.


I have a patient with persistent mature neutrophilia (or monocytosis). Will flow cytometry tell me if they are neoplastic?

No, our flow cytometry study is unable to differentiate between neoplastic and normal neutrophils or monocytes.


What is the sensitivity and specificity of the PARR and flow cytometry test?

  1. We estimate that in dogs, the PARR assay is 94% specific for lymphoid neoplasia, and the sensitivity is 75%.

  2. We estimate that in cats, the PARR assay has similar specificity to dogs (greater than 90%). In cats, the sensitivity of the PARR assay is estimated to be about 65%.

  3. Flow cytometry is an interpretive test. Therefore, we do not have sensitivity and specificity values for this diagnostic test.

How much blood should I send for the PARR and/or flow cytometry?

  1. Please send one purple top tube for PARR. We need a minimum of 100 microliters of blood.

  2. Please send at least 0.5 ml of blood for flow cytometry. Please send an additional purple top tube if you would like to have a CBC completed at CSU.

  3. See the Flow Cytometry Submission Instructions for more details.

Can I forward slides from another lab?

Yes, please be sure to have them send a sample submission form with the slides!


What is the difference between flow cytometry and PARR?

  1. The PARR assay is a PCR assay in which we are amplifying DNA. The results tell us if the majority of cells in the sample are derived from the same original clone (most consistent with neoplasia), or from multiple clones (most consistent with a reactive process). Here is a review of this methodology, "Molecular diagnostics of hematologic malignancies".

  2. The flow cytometry study involves staining live cells with labeled antibodies that bind to proteins expressed on the cell surface. Different types of lymphocytes express different protein (for example T cells express the protein CD3, and B cells express the protein CD21). The cells are analyzed on a flow cytometer, which tells us how many cells of each type are present. This information allows us to determine the lineage of the cells present, and whether they are homogeneous (more consistent with neoplasia) or heterogeneous (more consistent with a reactive process). Workman et al (Vet Clinics Small Animal 2003, 1379 – 1399) contains additional information about this assay.

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Fort Collins CO 80523-1619​
This is a mailing address for correspondence, not the address for shipping samples. See submission form for sample shipping address.

​(970) 491-1170

​(970) 491-4242