Cell Culture Medium (IV)

The Complete Culture Medium For Culturing Cells Is Generally Composed Of Basic Culture Medium (such As MEM) And Additives (serum Or Cell Growth Factor). The Formula Of The Culture Medium Will Continue To Improve With The Nutrition Required By The Cells. The Same Is True Of Antibiotics. Too Much Use Of Broad-spectrum Antibiotics Will Lead To The Improvement Of Cell Tolerance, Resulting In Resistance. Some Teachers Even Choose Not To Use Antibiotics To Culture Cells For The Accuracy Of The Experiment. 1、 The Vast Majority Of Basic Culture Media Are Based On Balanced Salt Solution (BSS). Amino Acids, Vitamins And Other Nutrients With Similar Concentrations In Serum Are Added. The Most Common Biological Medium Is Dulbecco ` S Modified Medium DMEM, Which Contains The Same Nutrients As MEM, But The Concentration Is 2-4 Times Higher. When Selecting A Certain Medium For Cell Culture, You Should Carefully Understand The Composition Table And Select The Medium Suitable For Cell Growth. Generally Speaking, 1640 Medium Is Used For Suspension Cells, While DMEM Is Most Common For Adherent Cells. Glutamic Acid Has A Higher Concentration Than Other Amino Acids In Some Media Because Of Its Instability And Its Common Use As A Carbon Source In Many Cell Cultures. MEM And F12 Should Be Balanced With 5% CO2. DMEM Contains Higher Concentration Of NaCO3. When Culturing Sensitive Nerve Cells, 10% CO2 Should Be Used To Balance. Of Course, It Can Also Be Used At A Lower CO2 Concentration. The Components Of These Basic Culture Media Are Based On The Study Of The Growth Of Different Cell Lines, But They Can Also Be Used In Primary Culture With Relatively Satisfactory Results. In Principle, HEPES, As A Buffer, Can Be Used To Replace Bicarbonate To Remove The Restriction Of High Concentration CO2 Culture Environment. It Is Not So Simple In Practice. Obviously, Dissolved CO2 And Bicarbonate Are Important For Good Cell Growth. Leiboviz ` S L15 Culture Medium Uses The Distinctive BSS As The Basis. It Contains High Concentrations Of Amino Acids To Improve The Buffer Capacity. Galactose Is Used As The Carbon Source In The Culture Medium To Prevent The Formation Of Lactic Acid In The Culture Medium. A Small Amount Of Dissolved CO2 Is Produced By Pyruvate Metabolism. Therefore, Cells Cultured In L-15 Medium Generally Need To Be Sealed In Culture Bottles Or Cultured In 100% Air. 2、 Serum Cells Cannot Survive In Simple Basic Culture Medium. In Special Cell Culture, Certain Nutrients And Growth Factors Must Be Provided To Enable Cells To Grow And Maintain Growth Status. Serum Is Often Added To The Basic Medium, And The Final Concentration Of Serum Is Usually 5~20%. The Source Of Serum For Special Use Must Be Determined By Experience. The Widely Used Serum Types Include Horse Serum And Fetal Bovine Serum. The Fetal Bovine Serum Is Rich In Mitotic Factors, Which Is Often Selected As The Serum For Proliferation Of Cells, As Well As For Cell Lines And Primary Culture. Horse Serum Is Often Used To Culture Neurons After Mitosis. Different Batches Of Serum Contain Different Components, So The Serum Should Be Tested Before Use. Most Reagent Manufacturers Provide Samples With Satisfactory Batch Numbers, So That We Can Get Enough Serum For One Year At A Time. III. The Most Commonly Used Antibiotics In Cell Culture Are Penicillin (commonly Used Concentration Is 25-100ui/ml) And Streptomycin (25-100 μ G/ml）。 The Two Antibiotics Are Often Mixed. In Some Laboratories, They Are Routinely Added To All Media. Gentamicin (10~100 μ G/ml) Usually Has Broad-spectrum Antibacterial Effect And Solution Stability, Which Is Often Used In General Laboratories. 4、 The Maintained Culture Should Be Kept In The Incubator. The Incubator Can Automatically Mix O2 And CO2 To Quickly Meet The Design Requirements Of The Culture Medium. The Oxygen Concentration In The Air Is Much Higher Than That In The Blood And Cerebrospinal Fluid. High Humidity Can Avoid The Evaporation Of The Culture Medium In The Culture Dish. To Keep The Humidity In The Incubator, A Large Basin Of Water Is Usually Placed At The Bottom Of The Incubator. This Water Should Be Changed Frequently, And The Water Container Should Be Disinfected Frequently To Prevent Mold Growth. If The Incubator Has Been Seriously Polluted By Mold Spores, It Will Be Very Difficult To Completely Remove The Pollution. When The Culture Must Be Kept In The Incubator For A Long Time, The Bottles And Dishes With Less Culture Medium Should Be Used, And The Lid Should Be Tightly Covered To Avoid Evaporation, Or The Corresponding Incubator With Proportional Air Supply Should Be Used. The Precise Adjustment Of Temperature Should Be Checked Regularly. The Incubator Temperature Is Usually Set At 37 ℃ Or Lower. Cells Can Have A Longer Tolerance Limit At Low Temperature, But When The Temperature Rises To 39 ℃, They Will Die Within A Few Hours.