the medical procedure for drawing a sample of venous blood into a vacuum tube is known as peripheral venous catheter.
the medical procedure for drawing a sample of venous blood into a vacuum tube is known as peripheral venous catheter.
the medical procedure for drawing a sample of venous blood into a vacuum tube is known as?
peripheral venous catheter
venous blood is typically colder than arterial blood, and has a lower oxygen content and ph. it also has lower concentrations of glucose and other nutrients, and has higher concentrations of urea and other waste products. the difference in the oxygen content of arterial blood and venous blood is known as the arteriovenous oxygen difference.









































most medical laboratory tests are conducted on venous blood, with the exception of arterial blood gas tests. venous blood is obtained for lab work by venipuncture (also called phlebotomy), or by finger prick for small quantities.









































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venous blood
dna methylation allows for several tissues to be analyzed in one assay as well as for small amounts of body fluid to be identified with the use of extracted dna.usually, the two approaches of dna methylation are either methylated-sensitive restriction enzymes or treatment with sodium bisulphite. methylated sensitive restriction enzymes work by cleaving specific cpg, cytosine and guanine separated by only one phosphate group, recognition sites when the cpg is methylated. in contrast, un-methylated cytosines are transformed to uracil and in the process methylated cytosines remain methylated. in particular, methylation profiles can provide insight on when or how body fluids were left at crime scenes, identify the kind of body fluid, and approximate age, gender, and phenotypic characteristics of perpetrators. research indicates various markers that can be used for dna methylation.deciding which marker to use for an assay is one of the first steps of identification of body fluids. in general, markers are selected by examining prior research conducted. identification markers that are chosen should give a positive result for one type of cell. one portion of chromosome that is an area of focus when conducting dna methylation are tissue-specific differentially methylated regions, t-dmrs.the degree of methylation for the t-dmrs ranges depending on the body fluid. a research team developed a marker system that is two-fold. the first marker is methylated only in the target fluid while the second is methylated in the rest of the fluids. for instance, if venous blood marker a is un-methylated and venous blood marker b is methylated in a fluid, it indicates the presence of only venous blood. in contrast, if venous blood marker a is methylated and venous blood marker b is un-methylated in some fluid, then that indicates venous blood is in a mixture of fluids. some examples for dna methylation markers are mens1(menstrual blood), spei1(saliva), and sperm2(seminal fluid).
dna methylation