BIOMED NOTES 24/25

Reflex Maintain homeostasis  Automatic action  Maintain balance and posture  Brain reflex center in brain stem  Class: Development: innate & acquire Response: somatic & visceral Complexity of circuit: mono & polysynaptic  Processing site: spinal & cranial  Polysynaptic: Golgi tendon  Monitor tension during contraction  Prevent tear or break of tendon  Stimulate receptor when stretch to dangerous degree  Greater tension greater inhibitory effect on motor neurons  Withdrawal  Move affected part away from stimulus  Flexor contract  Extensor relax  Crossed extensor  Contralateral + flexor  Flexor contract  Extensor relax  Crossed extensor occurs simultaneously同时发生, excitatory interneurons stimulate extensor, inhibitory interneurons relax flexor, leg straighten support shift in weight  Reflex assessment  Babinski  Dorsiflexion, plantar flexion, spreading of toes Occur...

You are given a suspension of cells at a concentration of 5 × 10⁵ cells/ml. You are asked to plate the cells for single-cell cloning using a 24-well plate, where each well contains 500 μl of culture media and should ideally contain 1 cell. How many times should you dilute the original cell suspension to achieve this? 先要知道final是5×10⁵ initial就是说明一个well里有500ul=0.5ml=1 cells 那1ml就是2cells 所以initial是2cells/ul dilution factor套公式是final/initial=250k 怎么算dilution factor可以用either 250k=100*100*25 或 100*50*50 这时就是用总额1ml来算的话，应该是 10ul of 5×10⁵ + 990ul Media = 100x 10ul of 5×10³ + 990ul Media = 10000x 40ul of 5×10¹ + 960ul Media  其实也就是  5×10⁵ = 500k 5×10³=5k 5×10¹=50 500k÷5k÷50=2cells/ml volume是算DF得出来的 10ul+990ul=100x 1000/10 DF 40+960/40=25x 20+980/20=50x Primary culture b4 subculture acquisition, isolation, disaggregation, culture after seeding  human use JKEUPM animal use IACUC mouse embryo:  undifferentiated mesenchymal cells full term 19-21d organ form at 9d - cells w less tiss...