Demacker P N, Vos-Janssen H E, Jansen A P, van 't Laar A
Clin Chem. 1977 Jul;23(7):1238-44.
We evaluated the dual-precipitation method for quantitative measurement of lipoproteins as described by Wilson and Spiger [J. Lab. Clin. Med. 82, 473 (1973)] for normo- and hyperlipemic sera, by comparison with the results obtained with ultracentrifugation. If serum with an above-normal triglyceride concentration is analyzed, the very-low-density lipoprotein cholesterol value obtained with the precipitation method is usually too low. For measurement of high-density lipoprotein cholesterol the ultracentrifugation and precipitation procedures give comparable results, but the latter method is preferred because sinking pre-beta-lipoproteins present in the high-density lipoprotein fraction isolated by means of the ultracentrifuge may result in falsely high values for cholesterol in that fraction. Therefore, at least for the determination of very-low-density lipoprotein cholesterol in hyperlipemic serum, the use of an ultracentrifuge remains necessary. Because few laboratories have an ultracentrifuge at their disposal, it seemed important to look at the stability of sera in view of the forwarding of samples. Also, a way of increasing the efficiency of the ultracentrifuge was studied. Sera can be stored for a week at 4 degrees C or for 54 h at room temperature without noticeable effect on lipoprotein values. Moreover, reliable values can be obtained with an ultracentrifugation time of 8 h (0.8 X 10(8) g-min).
我们按照Wilson和Spiger [《实验室与临床医学杂志》82, 473 (1973)]所描述的双沉淀法，对正常血脂和高血脂血清中的脂蛋白进行定量测量，并与超速离心法得到的结果进行比较。如果分析甘油三酯浓度高于正常水平的血清，沉淀法得到的极低密度脂蛋白胆固醇值通常过低。对于高密度脂蛋白胆固醇的测量，超速离心法和沉淀法给出的结果相当，但后一种方法更可取，因为通过超速离心分离出的高密度脂蛋白组分中存在的前β-脂蛋白下沉可能导致该组分中胆固醇值出现假高。因此，至少对于高血脂血清中极低密度脂蛋白胆固醇的测定，使用超速离心机仍然是必要的。由于很少有实验室能够使用超速离心机，考虑到样本的转送，研究血清的稳定性似乎很重要。此外，还研究了提高超速离心机效率的方法。血清可以在4℃下保存一周或在室温下保存54小时，而对脂蛋白值没有明显影响。此外，超速离心8小时（0.8×10⁸克-分钟）可获得可靠的值。
