To collect and preserve glioblastoma tissue during standard of care tumor resection surgery and blood for future molecular and genetic testing. Tissue for research will be collected from three different regions within the same tumor to study how these regions differ in their structure, DNA, and RNA and also to compare the data obtained from this testing to imaging data found in the medical record. The goal of this study is to help us better understand what the glioblastoma tumor tissue looks like and how it functions. This understanding can lead to new therapies for the treatment of glioblastoma in the future.

Inclusion Criteria:

1. Have the appearance of high-grade glioma on magnetic resonance (MR) imaging if allowed to consent and will undergo the procedure if the frozen is consistent with glioblastoma or gliosarcoma OR Patients with a history of histologically confirmed diagnosis of World Health Organization Grade glioblastoma or gliosarcoma that are undergoing repeat resection of a recurrent tumor as identified on preoperative MR imaging
2. Aged ≥ 18 years old
3. Contrast-enhancing tumor volume of at least 10 cc on the preoperative, volumetric MRI within 1 month prior to surgery
4. Provision of signed and dated informed consent form by participant or legally authorized representative (LAR), if applicable

Exclusion Criteria:

1. Has a history or current evidence of any medical condition, therapy, or laboratory abnormality that might confound the results of the study or is not in the best interest of the participant, in the opinion of the treating investigator.

Adults with GBM or gliosarcoma undergoing standard of care tumor resection surgery.