Recap of Monday's LIVE Study Session
Greetings Gang 😈🤪 HERE IS THE RECAP OF MONDAY'S LIVE STUDY SESSION ‼️✨There is another one tomorrow evening at 3PM PST/4PM MST/5PM CST/6PM EST https://fathom.video/share/DTxwmHy1sLVpYaFTAkb53canXdH-9NMC VIEW RECORDING - 88 mins (No highlights) Meeting Purpose Review ASCP practice questions across multiple lab disciplines. Key Takeaways - Lewis Antigens are Adsorbed: Lewis antigens are unique because they are not intrinsic to RBCs; they are passively adsorbed from plasma. This key distinction from other blood groups is a common exam point. - Yersinia enterocolitica is a Transfusion Risk: This organism's ability to grow at 4°C (blood storage temperature) makes it a critical cause of transfusion-related septicemia, a high-yield exam fact. - MDS Cytopenia is from Apoptosis: Myelodysplastic Syndromes (MDS) cause low cell counts (cytopenia) because the bone marrow produces abnormal cells that are destroyed via apoptosis before they can be released into circulation. - PCR Steps are Denaturation, Annealing, Extension (DAE): This is the correct sequence for PCR. "Hot start" methods prevent non-specific reactions by keeping the polymerase inactive until the optimal temperature is reached. Topics Molecular Biology & Genetics - DNA Nucleotide Composition:A DNA nucleotide consists of deoxyribose, phosphate, and a nitrogenous base (A, T, C, or G).Ribose and Uracil (U) are components of RNA only. - Huntington's Disease:Caused by a trinucleotide repeat: CAG.CGG is associated with Fragile X syndrome. - Second Messengers (cAMP vs. cGMP):cAMP is generated from ATP by adenyl cyclase.cGMP is generated from GTP by guanylyl cyclase.Clinical Relevance:cGMP → Blood vessel relaxation (vasodilation), explaining the action of drugs like nitroglycerin and .cAMP → Bronchodilation, explaining the action of drugs like albuterol.Lab Takeaway: High hormone levels with no expected effect can indicate a signal transduction problem (e.g., Type 2 Diabetes), not a hormone production issue. - PCR Steps & Hot Start PCR:Standard PCR Sequence: Denaturation → Annealing → Extension (DAE).Hot Start PCR: Prevents non-specific reactions by keeping the polymerase inactive until the optimal temperature is reached.Methods:Keeping the reaction on ice until the thermal cycler heats.Separating polymerase and primers with a wax bead that melts at high temperature.Using modified polymerases that are only activated at high temperatures. - MALDI-TOF Mass Spectrometry:Mechanism: Identifies bacteria by measuring the mass-to-charge ratio of molecules.Process: A laser vaporizes the sample, and the "time of flight" of the molecules is compared to a database for identification.Key Point: The laser does not amplify bacteria; it vaporizes them.