Bomalecular testing

The invention of the polymerase chain reaction (PCR) method was one of the most significant achievements in the field of molecular biology. In 1995, the inventor was awarded Nobel Prize. PCR is widely used to detect a wide range of diseases.

A focused segment of DNA is amplified due to a multiple replication of a standard PCR cycle, which consists of three consecutive stages. PCR enables to amplify a focused DNA as many times as needed. Thus, we may manipulate microsamples and get a prompt high sensitivity response (10-5-10-7).

At our laboratory PCR is used:

• to detect genetic markers of acute and chronic leukemias;
• to diagnose viral infections;
• to monitor hematopoietic chimerism in case of allogeneic bone marrow transplantation.

Detection of a chimeric BCR-ABL gene and its types

mRNA of BCR-ABL gene is found in approximately 97-98% of the patients with chronic myeloid leukemia. Thus, a doctor may diagnose a disease even if the results of cytogenetic tests are unclear.

According to our records, b3a2 type of BCR-ABL gene was found in 30% of patients over 18, b2a2 type  – in 43% of patients and e1a2 type – in 1% of patients. Besides, we detected mixed types of chimeric BCR-ABL gene ‑ b2a2 + e1a2 – in 3% of patients, and a rearranged type of BCR-ABL gene was detected in one case. We marked it as “not b3a2, not b2a2, not e1a2”

PCR testing of viral infections

It is more effective to use PCR to detect viral infections in the patients, who receive immunosuppressive therapy after transplantation. Since the production of antibodies in such patients is suppressed, a standard ELISA assay is less clear. At our laboratory, we use PCR to detect herpes, CMV, hepatitis, etc. PCR enables to detect up to 100 or less viral particles in one sample.

Assessment of hematopoietic chimerism

It is important to learn what cells, donor or recipient, help to restore hematopoiesis in case of allogeneic transplantation. The amplification of DNA from a recipient’s blood enables to find out if there any admixture of donor’s cells (less than 1%) and monitor the dynamics of bone marrow survival.

In this case, the donor and the recipient of bone marrow had different alleles of DNA loci CSF1PO, TРOX, THO1 and P13B. It helps to monitor the dynamics of the survival of bone marrow cells. Picture 3 shows that a mixed chimerism occurred on day 28-45, when blood simultaneously contained the donor’s and recipient’s cells. On day 60, only the recipient’s DNA was determined. Thus, we concluded the failure of bone marrow transplantation.